* 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.

The code in the Tendermint repository makes heavy use of import aliasing.
This is made necessary by our extensive reuse of common base package names, and
by repetition of similar names across different subdirectories.

Unfortunately we have not been very consistent about which packages we alias in
various circumstances, and the aliases we use vary. In the spirit of the advice
in the style guide and https://github.com/golang/go/wiki/CodeReviewComments#imports,
his change makes an effort to clean up and normalize import aliasing.

This change makes no API or behavioral changes. It is a pure cleanup intended
o help make the code more readable to developers (including myself) trying to
understand what is being imported where.

Only unexported names have been modified, and the changes were generated and
applied mechanically with gofmt -r and comby, respecting the lexical and
syntactic rules of Go.  Even so, I did not fix every inconsistency. Where the
changes would be too disruptive, I left it alone.

The principles I followed in this cleanup are:

- Remove aliases that restate the package name.
- Remove aliases where the base package name is unambiguous.
- Move overly-terse abbreviations from the import to the usage site.
- Fix lexical issues (remove underscores, remove capitalization).
- Fix import groupings to more closely match the style guide.
- Group blank (side-effecting) imports and ensure they are commented.
- Add aliases to multiple imports with the same base package name.

Closes #6551 

Simple PR to add the total gas used in the block by adding the gas used in all the transactions. 
This adds a `TotalGasUsed` field to `coretypes.ResultBlockResults`.

Its my first PR to the repo so let me know if there is anything I am missing!

@fedekunze In case you want to take a look

Fixes #5377 and comments in #4588 (review).

## Description

Make an interface for the state store. 

Closes: #5213

## Description

the second part of state proto migration

Closes: #XXX

Closes https://github.com/tendermint/tendermint/issues/3857

Moves `lib/` folder to `jsonrpc/`.

Renames:

**packages**

`rpc` package -> `jsonrpc` package
`rpcclient` package -> `client` package
`rpcserver` package -> `server` package

**structs and interfaces**

```
JSONRPCClient to Client
JSONRPCRequestBatch to RequestBatch
JSONRPCCaller to Caller
```

**functions**

```
StartHTTPServer to Serve
StartHTTPAndTLSServer to ServeTLS

rpc/jsonrpc/client: rename NewURIClient to NewURI

NewJSONRPCClient to New
NewJSONRPCClientWithHTTPClient to NewWithHTTPClient
NewWSClient to NewWS
```

**misc**

- unexpose `ResponseWriterWrapper`
- remove unused http_params.go

Closes #3433

* Added BlockStore.DeleteBlock()

* Added initial block pruner prototype

* wip

* Added BlockStore.PruneBlocks()

* Added consensus setting for block pruning

* Added BlockStore base

* Error on replay if base does not have blocks

* Handle missing blocks when sending VoteSetMaj23Message

* Error message tweak

* Properly update blockstore state

* Error message fix again

* blockchain: ignore peer missing blocks

* Added FIXME

* Added test for block replay with truncated history

* Handle peer base in blockchain reactor

* Improved replay error handling

* Added tests for Store.PruneBlocks()

* Fix non-RPC handling of truncated block history

* Panic on missing block meta in needProofBlock()

* Updated changelog

* Handle truncated block history in RPC layer

* Added info about earliest block in /status RPC

* Reorder height and base in blockchain reactor messages

* Updated changelog

* Fix tests

* Appease linter

* Minor review fixes

* Non-empty BlockStores should always have base > 0

* Update code to assume base > 0 invariant

* Added blockstore tests for pruning to 0

* Make sure we don't prune below the current base

* Added BlockStore.Size()

* config: added retain_blocks recommendations

* Update v1 blockchain reactor to handle blockstore base

* Added state database pruning

* Propagate errors on missing validator sets

* Comment tweaks

* Improved error message

Co-Authored-By: Anton Kaliaev <anton.kalyaev@gmail.com>

* use ABCI field ResponseCommit.retain_height instead of retain-blocks config option

* remove State.RetainHeight, return value instead

* fix minor issues

* rename pruneHeights() to pruneBlocks()

* noop to fix GitHub borkage

Co-authored-by: Anton Kaliaev <anton.kalyaev@gmail.com>

* format: add format cmd & goimport repo

- replaced format command
- added goimports to format command
- ran goimports

Signed-off-by: Marko Baricevic <marbar3778@yahoo.com>

* fix outliers & undo proto file changes

* added RPC method block_by_hash

* created hash => height

* changes typings

* block_by_hash changes

* Update store/store.go

Co-Authored-By: Anton Kaliaev <anton.kalyaev@gmail.com>

* Update store/store.go

Co-Authored-By: Anton Kaliaev <anton.kalyaev@gmail.com>

* Update store/store.go

Co-Authored-By: Anton Kaliaev <anton.kalyaev@gmail.com>

* Update store/store.go

Co-Authored-By: Anton Kaliaev <anton.kalyaev@gmail.com>

Co-authored-by: Marko <marbar3778@yahoo.com>
Co-authored-by: Anton Kaliaev <anton.kalyaev@gmail.com>

BREAKING

Example response:

```json
{
  "jsonrpc": "2.0",
  "id": "",
  "result": {
    "height": "2109",
    "txs_results": null,
    "begin_block_events": null,
    "end_block_events": null,
    "validator_updates": null,
    "consensus_param_updates": null
  }
}
```

Old result consisted of ABCIResponses struct and height. Exposing
internal ABCI structures (which we store in state package) in RPC seems
bad to me for the following reasons:

1) high risk of breaking the API when somebody changes internal structs
(HAPPENED HERE!)
2) RPC is aware of ABCI, which I'm not sure we want