This pull request merges in the changes for implementing Proposer-based timestamps into `master`. The power was primarily being done in the `wb/proposer-based-timestamps` branch, with changes being merged into that branch during development. This pull request represents an amalgamation of the changes made into that development branch. All of the changes that were placed into that branch have been cleanly rebased on top of the latest `master`. The changes compile and the tests pass insofar as our tests in general pass.

### Note To Reviewers
 These changes have been extensively reviewed during development. There is not much new here. In the interest of making effective use of time, I would recommend against trying to perform a complete audit of the changes presented and instead examine for mistakes that may have occurred during the process of rebasing the changes. I gave the complete change set a first pass for any issues, but additional eyes would be very appreciated. 

In sum, this change set does the following:
closes #6942 
merges in #6849

This is the interface shared by types that can be used as event data in, for
example, subscriptions via the RPC.

To be compatible with the RPC service, data need to support JSON encoding.
Require this as part of the interface.

Remove the pubsub.Query interface and instead use the concrete query type.
Nothing uses any other implementation but pubsub/query.

* query: remove the error from the Matches method
* Update all usage.

There are no further uses of this package anywhere in Tendermint.
All the uses in the Cosmos SDK are for types that now work correctly with the
standard encoding/json package.

The main change here is to use encoding/json to encode and decode RPC 
parameters, rather than the custom tmjson package. This includes:

- Update the HTTP POST handler parameter handling.
- Add field tags to 64-bit integer types to get string encoding (to match amino/tmjson).
- Add marshalers to struct types that mention interfaces.
- Inject wrappers to decode interface arguments in RPC handlers.

Avert panics for corner cases (e.g., nil pointers) and for implementations that
reside only on the pointer type. Add documentation and tests.

The problem with the `TestStateFullRound1` is that the state that we are observeing, `cs`, can advance to the next height before we query its data. Specifically, on line `388`, when we called `validatePrevote`, the `cs` State had already advanced to height 2, so querying that State for the votes of height 1 either yielded nil or an erroneous value. This change adds a `ensurePrevoteMatch` function that checks that the prevote occurred and checks that it is for the expected block at the same time. If this change looks reasonable I can just apply the same fix to all of the places where we perform `ensurePrevote` followed by `validatePrevote` to use this function instead.

*light: rpc /status returns status of light client ; code refactoring
 light: moved lightClientInfo into light.go, renamed String to ID
test/e2e: Return light client trusted height instead of SyncInfo trusted height
test/e2e/start.go: Not waiting for light client to catch up in tests. Removed querying of syncInfo in start if the node is a light node

* light: Removed call to primary /status. Added trustedPeriod to light info
* light/provider: added ID function to return IP of primary and witnesses
* light/provider/http/http_test: renamed String() to ID()

Fixes #7593

This change has two main effects:

1. Remove most of the Async methods from the abci.Client interface.
   Remaining are FlushAsync, CommitTxAsync, and DeliverTxAsync.

2. Rename the synchronous methods to remove the "Sync" suffix.

The rest of the change is updating the implementations, subsets, and mocks of
the interface, along with the call sites that point to them.

* Fix stringly-typed mock stubs.
* Rename helper method.

The test filter was looking for "TestGoFiles", which does not include tests in
a separate package (e.g., "package foo_test" for "package foo").
This caused several packages not to be tested in CI, including:

  github.com/tendermint/tendermint/abci/client
  github.com/tendermint/tendermint/crypto
  github.com/tendermint/tendermint/crypto/tmhash
  github.com/tendermint/tendermint/internal/eventbus
  github.com/tendermint/tendermint/internal/evidence
  github.com/tendermint/tendermint/internal/inspect
  github.com/tendermint/tendermint/internal/jsontypes
  github.com/tendermint/tendermint/internal/libs/protoio
  github.com/tendermint/tendermint/internal/libs/sync
  github.com/tendermint/tendermint/internal/p2p/pex
  github.com/tendermint/tendermint/internal/pubsub
  github.com/tendermint/tendermint/internal/pubsub/query
  github.com/tendermint/tendermint/internal/pubsub/query/syntax
  github.com/tendermint/tendermint/internal/state/indexer
  github.com/tendermint/tendermint/internal/state/indexer/block/kv
  github.com/tendermint/tendermint/libs/json
  github.com/tendermint/tendermint/libs/log
  github.com/tendermint/tendermint/libs/os
  github.com/tendermint/tendermint/light
  github.com/tendermint/tendermint/light/provider/http
  github.com/tendermint/tendermint/privval/grpc
  github.com/tendermint/tendermint/proto/tendermint/blocksync
  github.com/tendermint/tendermint/proto/tendermint/consensus
  github.com/tendermint/tendermint/proto/tendermint/statesync
  github.com/tendermint/tendermint/rpc/client
  github.com/tendermint/tendermint/rpc/client/mock
  github.com/tendermint/tendermint/test/e2e/tests
  github.com/tendermint/tendermint/test/fuzz/mempool
  github.com/tendermint/tendermint/test/fuzz/p2p/secretconnection
  github.com/tendermint/tendermint/test/fuzz/rpc/jsonrpc/server

Updates #7626 and #7634.

During file rotation and WAL shutdown, there was a race condition between users
of an autofile and its termination. To fix this, ensure operations on an
autofile are properly synchronized, and report errors when attempting to use an
autofile after it was closed.

Notably:

- Simplify the cancellation protocol between signal and Close.
- Exclude writers to an autofile during rotation.
- Add documentation about what is going on.

There is a lot more that could be improved here, but this addresses the more
obvious races that have been panicking unit tests.

Reverts and improves on #7622. The problem turns out not to be on the PEX
channel side, but on the pass-through (Go) channel.

There was a path on which computing the next delivery time did not hold the
lock, defying the admonition on its comment.

## What does this pull request do?
This pull requests adds two metrics intended for use in calculating an experimental value for `MessageDelay`.

The metrics are as follows:
```
# HELP tendermint_consensus_complete_prevote_message_delay Difference in seconds between the proposal timestamp and the timestamp of the prevote that achieved 100% of the voting power in the prevote step.
# TYPE tendermint_consensus_complete_prevote_message_delay gauge
tendermint_consensus_complete_prevote_message_delay{chain_id="test-chain-aZbwF1"} 0.013025505

# HELP tendermint_consensus_quorum_prevote_message_delay Difference in seconds between the proposal timestamp and the timestamp of the prevote that achieved a quorum in the prevote step.
# TYPE tendermint_consensus_quorum_prevote_message_delay gauge
tendermint_consensus_quorum_prevote_message_delay{chain_id="test-chain-aZbwF1"} 0.013025505
```

## Why this change?

 For more information on what these metrics are calculating, see #7202. The aim is to merge to backport these metrics to v0.34 and run nodes on a few popular chains with these metrics to determine the experimental values for `MessageDelay` on these popular chains and use these to select our default `SynchronyParams.MessageDelay` value.

## Why Gauges for the metrics?
Gauges allow us to overwrite the metric on each successive observation. We can then capture these metrics over time to track the highest and lowest observed value.

This commit changes the behaviour of the /unconfirmed_txs endpoint by replacing limit with a page and perPage parameter for pagination.
The test case for unconfirmed_txs have been accommodated to properly test this change and the documentation for the API as well.

The custom error types in the provider package did not propagate their wrapped
underlying reasons, making it difficult for the test to check that the correct
error was observed.

- Fix the custom errors to have a true underlying error (not just a string).
- Add Unwrap methods to support inspection by errors.Is.
- Update usage in a few places.
- Fix the test to check for acceptable variation.

Fixes #7609.

After writing and then reading a bunch of random messages, the test was
checking that it did not read the same number of messages that it wrote.
The sense of this check was inverted; they should match.

Introduced by accident in #7522. I'm not sure why this did not show up in CI.

Edit: I now know why it didn't show up in ci: #7608.

Add package jsontypes that implements a subset of the custom libs/json 
package. Specifically it handles encoding and decoding of interface types
wrapped in "tagged" JSON objects. It omits the deep reflection on arbitrary
types, preserving only the handling of type tags wrapper encoding.

- Register interface types (Evidence, PubKey, PrivKey) for tagged encoding.
- Update the existing implementations to satisfy the type.
- Register those types with the jsontypes registry.
- Add string tags to 64-bit integer fields where needed.
- Add marshalers to structs that export interface-typed fields.

Instead of taking a comma-separated string of parameter names, take each
parameter name as a separate argument. Now that we no longer have an extra flag
for caching, this fits nicely into a variadic trailer.

* Update all usage of NewRPCFunc and NewWSRPCFunc.

Define interfaces for the various methods a service may implement.  This is
basically just the set of things on Environment that are exported as RPCs, but
these are also implemented by the light proxy.

* internal/rpc: use NewRoutesMap to construct routes on service start
* light/proxy: use NewRoutesMap to construct RPC routes

We should not set cache-control headers on RPC responses. HTTP caching
interacts poorly with resources that are expected to change frequently, or
whose rate of change is unpredictable.

More subtly, all calls to the POST endpoint use the same URL, which means a
cacheable response from one call may actually "hide" an uncacheable response
from a subsequent one. This is less of a problem for the GET endpoints, but
that means the behaviour of RPCs varies depending on which HTTP method your
client happens to use. Websocket requests were already marked statically
uncacheable, adding yet a third combination.

To address this:

- Stop setting cache-control headers.
- Update the tests that were checking for those headers.
- Remove the flags to request cache-control.

Apart from affecting the HTTP response headers, this change does not modify the
behaviour of any of the RPC methods.

* Rename rpctypes.Context to CallInfo.

Add methods to attach and recover this value from a context.Context.

* Rework RPC method handlers to accept "real" contexts.

- Replace *rpctypes.Context arguments with context.Context.
- Update usage of RPC context fields to use CallInfo.

Where possible, replace uses of the custom JSON library with the standard
library. The custom library treats interface and unnamed lteral types
differently, so this change avoids those even where it would probably be safe
to switch them.