Addresses one of the concerns with #7041.

Provides a mechanism (via the RPC interface) to delete a single transaction, described by its hash, from the mempool. The method returns an error if the transaction cannot be found. Once the transaction is removed it remains in the cache and cannot be resubmitted until the cache is cleared or it expires from the cache.

Co-authored-by: Callum Waters <cmwaters19@gmail.com>

## Description

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


Closes: #XXX

## Description

This PR removes simple prefix from all types in the crypto/merkle directory.

The two proto types `Proof` & `ProofOp` have been moved to the `proto/crypto/merkle` directory.

proto messge `Proof` was renamed to `ProofOps` and `SimpleProof` message to `Proof`. 

Closes: #2755

* proto: move mempool to proto

- changes according to moving the mempool reactor to proto

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

Closes: #2883

* libs/common: Refactor libs/common 4

- move byte function out of cmn to its own pkg
- move tempfile out of cmn to its own pkg
- move throttletimer to its own pkg

ref #4147

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

* add changelog entry

* fix linting issues

Refs #3262

* Remove omitempty from *pb.go

- remove omitempty from *pb.go files
- added command to makefile for everytime `make protoc_all` is run

- open question:
  - Do we want to further remove omitempty from other places
	- https://github.com/tendermint/tendermint/blob/master/rpc/lib/types/types.go#L151
	- and other places
ref #3882

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

* bring back omitempty to *pb.go

* Update types/tx.go

* custom marshlers

* undo benchmark `omitepmty`

* golangci lint fix

* cleanup comments

* changelog_pending entry

* Remove unnecessary type conversions

* Consolidate repeated strings into consts

* Clothe return statements

* Update blockchain/v1/reactor_fsm_test.go

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

This PR repairs linter errors seen when running the following commands:
golangci-lint run --no-config --disable-all=true --enable=unconvert
golangci-lint run --no-config --disable-all=true --enable=goconst
golangci-lint run --no-config --disable-all=true --enable=nakedret

Contributes to #3262

As per conversation here: https://github.com/tendermint/tendermint/pull/3218#discussion_r251364041

This is the result of running the following code on the repo:

```bash
find . -name '*.go' | grep -v 'vendor/' | xargs -n 1 goimports -w
```

* Begin simple merkle compatibility PR

* Fix query_test

* Use trillian test vectors

* Change the split point per RFC 6962

* update spec

* refactor innerhash to match spec

* Update changelog

* Address @liamsi's comments

* Write the comment requested by @liamsi

* fix amino overhead computation for Tx:

- also count the fieldnum / typ3
- add method to compute overhead per Tx
- slightly clarify comment on MaxAminoOverheadForBlock
- add tests

* fix TestReapMaxBytesMaxGas according to amino overhead

* fix TestMempoolFilters according to amino overhead

* address review comments:

 - add a note about fieldNum = 1
 - add forgotten godoc comment

* fix and use sm.TxPreCheck

* fix test

* remove print statement

This is a performance regression, but will also spare the types directory
from knowing about RFC 6962, which is a more correct abstraction. For txs
this performance hit will be fixed soon with #2603. For evidence, the
performance impact is negligible due to it being capped at a small number.

* crypto/merkle: Remove byter in favor of plain byte slices

This PR is fully backwards compatible in terms of function output!
(The Go API differs though) The only test case changes was to refactor
it to be table driven.

* Update godocs per review comments

* first commit

finalize rebase

add protoc_merkle to Makefile

* in progress

* fix kvstore

* fix tests

* remove iavl dependency

* fix tx_test

* fix test_abci_cli

fix test_apps

* fix test_apps

* fix test_cover

* rm rebase residue

* address comment in progress

* finalize rebase

See ADR 020: Limiting txs size inside a block docs/architecture/adr-020-block-size.md

Refs #2035

This reverts commit d02c5d1e30.

This reverts commit 96a3502

uint64 is considered dangerous. the details will follow in a blog post.