* consensus: calculate prevote message delay metric (#7551)

## 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.

(cherry picked from commit 0c82ceaa5f)

# Conflicts:
#	consensus/metrics.go
#	consensus/state.go

* fix merge conflicts

Co-authored-by: William Banfield <4561443+williambanfield@users.noreply.github.com>
Co-authored-by: William Banfield <wbanfield@gmail.com>

## Description

Part of the issue is to add metrics to the websocket connection. It seems this would require some moving around of things in the node pkg. I opted to not make this change now, and wait for when we do a node pkg refactor. 

If someone disagrees with this appraoch please let me know, I can attempt to get metrics into the rpc layer.

There is not a need to update documentation as it already states this metric is a histogram..

Closes: #1791

## Description

Add missing metrics. 

`Blockchain/v2` exposes metrics for events. I don't find these as something a node operator should utilize as it does not bring insight. 

Closes: #XXX

Fixes #828. Adds state sync, as outlined in [ADR-053](https://github.com/tendermint/tendermint/blob/master/docs/architecture/adr-053-state-sync-prototype.md). See related PRs in Cosmos SDK (https://github.com/cosmos/cosmos-sdk/pull/5803) and Gaia (https://github.com/cosmos/gaia/pull/327).

This is split out of the previous PR #4645, and branched off of the ABCI interface in #4704. 

* Adds a new P2P reactor which exchanges snapshots with peers, and bootstraps an empty local node from remote snapshots when requested.

* Adds a new configuration section `[statesync]` that enables state sync and configures the light client. Also enables `statesync:info` logging by default.

* Integrates state sync into node startup. Does not support the v2 blockchain reactor, since it needs some reorganization to defer startup.

* prometheus/metrics: two new metrics for consensus

- add consensus_validator_power metric so if a node is a validator it can see its own power in prometheus
- add last_signed_height metric so if a node is a validator it can be aware of at which height the most recent time it signed.

- closes: #3773
- closes: #3083

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

* check if signature is present

* minor change and check if sig is not absent

* add changelog entry

* Update consensus/state.go

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

* Update CHANGELOG_PENDING.md

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

* Update CHANGELOG_PENDING.md

* add label with validator address

* change address to vali_address

* add metric missed blocks

* add changelog entry for missed blocks metric

* address naming & add docs

* add "chain_id" label for all metrics

Refs #3082

* fix labels extraction

* Add additional metrics
Continues addressing https://github.com/cosmos/cosmos-sdk/issues/2169.
* Add nop metrics to fix NPE
* Tweak buckets, code review
* Update buckets
* Update docs with new metrics
* Code review updates

* Add additional metrics to p2p and consensus
Partially addresses https://github.com/cosmos/cosmos-sdk/issues/2169.
* WIP
* Updates from code review
* Updates from code review
* Add instrumentation namespace to configuration
* Fix test failure
* Updates from code review
* Add quotes
* Add atomic load
* Use storeint64
* Use addInt64 in writePacketMsgTo

Otherwise, it's impossible to see outliers
https://github.com/tendermint/tendermint/issues/1835#issuecomment-402054099

This reverts commit d02c5d1e30.

This reverts commit 96a3502

- move prometheus metrics into internal packages
- *Option structs
- misc. format changes