This cleans up the `Router` code and adds a bunch of tests. These sorts of systems are a real pain to test, since they have a bunch of asynchronous goroutines living their own lives, so the test coverage is decent but not fantastic. Luckily we've been able to move all of the complex peer management and transport logic outside of the router, as synchronous components that are much easier to test, so the core router logic is fairly small and simple.

This also provides some initial test tooling in `p2p/p2ptest` that automatically sets up in-memory networks and channels for use in integration tests. It also includes channel-oriented test asserters in `p2p/p2ptest/require.go`, but these have primarily been written for router testing and should probably be adapted or extended for reactor testing.

This tightens up the `PeerManager` and related code, adds a ton of tests, and fixes a bunch of inconsistencies and bugs.

ref: #6005

## Description

Fixes the data race in usage of `WaitGroup`. Specifically, the case where we invoke `Wait` _before_ the first delta `Add` call when the current waitgroup counter is zero. See https://golang.org/pkg/sync/#WaitGroup.Add.

Still not sure how this manifests itself in a test since the reactor has to be stopped virtually immediately after being started (I think?).

Regardless, this is the appropriate fix.

closes: #5968

Fixes #5841.

Fixes #5843.

blockchain/vX reactor priority was decreased because during the normal operation
(i.e. when the node is not fast syncing) blockchain priority can't be
the same as consensus reactor priority. Otherwise, it's theoretically possible to
slow down consensus by constantly requesting blocks from the node.

NOTE: ideally blockchain/vX reactor priority would be dynamic. e.g. when
the node is fast syncing, the priority is 10 (max), but when it's done
fast syncing - the priority gets decreased to 5 (only to serve blocks
for other nodes). But it's not possible now, therefore I decided to
focus on the normal operation (priority = 5).

evidence and consensus critical messages are more important than
the mempool ones, hence priorities are bumped by 1 (from 5 to 6).

statesync reactor priority was changed from 1 to 5 to be the same as
blockchain/vX priority.

Refs https://github.com/tendermint/tendermint/issues/5816

The `NodeInfo` interface does not appear to serve any purpose at all, so I removed it and renamed the `DefaultNodeInfo` struct to `NodeInfo` (including the Protobuf representations). Let me know if this is actually needed for anything.

Only the Protobuf rename is listed in the changelog, since we do not officially support API stability of the `p2p` package (according to `README.md`). The on-wire protocol remains compatible.

Closes #5766

* memoize the scSchedulerFail error to avoid printing it every scheduleFreq
* blockchain/v2: modify switchIO funcs to accept peer instead of peerID

Closes: #5718

After a reactor has failed to parse an incoming message, it shouldn't output the "bad" data into the logs, as that data is unfiltered and could have anything in it. (We also don't think this information is helpful to have in the logs anyways.)

I introduced a new variable - syncEnded, which is now used to prevent
sending new events to channels (which would block otherwise) if reactor
is finished syncing

Closes #4591

Closes #5444

Now we record the fact that a peer does not have a requested block and later use this information to make a new request for the same block from another peer.

Refs #2888

after they were pruned by the scheduler

Closes #5513

also, since multiple StopPeerForError calls may be executed in parallel,
only execute StopPeerForError once

Closes #5541

Before: scheduler receives psBlockProcessed event, but does not mark block as processed because peer timed out (or was removed for other reasons) and all associated blocks were rescheduled.

After: scheduler receives psBlockProcessed event and marks block as processed in any case (even if peer who provided this block errors).

Closes #5387

When a peer is stopped due to some network issue, the Reactor calls scheduler#handleRemovePeer, which removes the peer from the scheduler. BUT the peer stays in the processor, which sometimes could lead to "duplicate block enqueued by processor" panic WHEN the same block is requested by the scheduler again from a different peer. The solution is to return scPeerError, which will be propagated to the processor. The processor will clean up the blocks associated with the peer in purgePeer.

Closes #5513, #5517

## Description

In protobuf `[]byte` is varint encoded. When adding txs to the block we were not taking this into account. 


Closes: #XXX

## Description

Add simple `NoBlockResponse` handling to blockchain reactor v1. I tested before and after with erik's e2e testing and was not able to reproduce the inability to sync after the changes were applied

Closes: #5394

evidence: modify evidence types (#5342)

light: detect light client attacks (#5344)

evidence: refactor evidence pool (#5345)

abci: application evidence prepared by evidence pool (#5354)

## Description

Make an interface for the state store. 

Closes: #5213

## Description

Check block protocol version in header validate basic. 

I tried searching for where we check the P2P protocol version but was unable to find it. When we check compatibility with a node we check we both have the same block protocol and are on the same network, but we do not check if we are on the same P2P protocol. It makes sense if there is a handshake change because we would not be able to establish a secure connection, but a p2p protocol version bump may be because of a p2p message change, which would go unnoticed until that message is sent over the wire.  Is this purposeful?

Closes: #4790

## Description

Enable errcheck linter throughout the codebase

Closes: #5059

## Description

Verify only +2/3 of the commit. 

Closes: #5259

Blockchain reactors were not updated to handle arbitrary initial height after #5191.

## Description

Add test vectors for all reactors

- [x] state-sync
- [x] privval
- [x] mempool
- [x] p2p
- [x] evidence
- [ ] light?

this PR is primarily oriented at testvectors for things going over the wire. should we expand the testvectors into types as well?

Closes: #XXX

Fixes #5192.

@liamsi Can you verify that the test vectors match the Rust implementation? I updated `ProofsFromByteSlices()` as well, anything else that should be updated?

While working on tendermint my colleague @jinmannwong fixed a few of the unit tests that we found to be flaky in our CI. We thought that you might find this useful, see below for comments.

## Description

This PR wraps the stdlib sync.(RW)Mutex & godeadlock.(RW)Mutex. This enables using go-deadlock via a build flag instead of using sed to replace sync with godeadlock in all files

Closes: #3242

## Description
linter version fix and run make format to have all ci run

Closes: #XXX

## Description

add more error checks to tests


gonna do a third PR that tackles the non test cases

- drop Height & Base from StatusRequest
It does not make sense nor it's used anywhere currently. Also, there
seem to be no trace of these fields in the ADR-40 (blockchain reactor
v2).

- change PacketMsg#EOF type from int32 to bool

check bcR.fastSync flag when "OnStop"

fix "service/service.go:161	Not stopping BlockPool -- have not been started yet	{"impl": "BlockPool"}" error when kill process

## Description

this PR adds test vectors for proto encoding. the main difference from amino was the removal of four bytes due to interface encoding.

should i add more cases?

Closes: #XXX

## Description

partially cleanup in preparation for errcheck

i ignored a bunch of defer errors in tests but with the update to go 1.14 we can use `t.Cleanup(func() { if err := <>; err != nil {..}}` to cover those errors, I will do this in pr number two of enabling errcheck.

ref #5059