* types: change `Commit` to consist of just signatures

These are final changes towards removing votes from commit and leaving
only signatures (see ADR-25)

Fixes #1648

* bring back TestCommitToVoteSetWithVotesForAnotherBlockOrNilBlock

+ add absent flag to Vote to indicate that it's for another block

* encode nil votes as CommitSig with BlockIDFlagAbsent

+ make Commit#Precommits array of non-pointers
because precommit will never be nil

* add NewCommitSigAbsent and Absent() funcs

* uncomment validation in CommitSig#ValidateBasic

* add comments to ValidatorSet funcs

* add a changelog entry

* break instead of continue

continue does not make sense in these cases

* types: rename Commit#Precommits to Signatures

* swagger: fix /commit response

* swagger: change block_id_flag type

* fix merge conflicts

replaces https://tendermint.com/docs" with "https://docs.tendermint.com/master"

and EventDataNewBlockHeader

https://www.jsonrpc.org/specification

What is done in this PR:

    JSONRPCClient: validate that Response.ID matches Request.ID I wanted
    to do the same for the WSClient, but since we're sending events as
    responses, not notifications, checking IDs would require storing
    them in memory indefinitely (and we won't be able to remove them
    upon client unsubscribing because ID is different then).

    Request.ID is now optional. Notification is a Request without an ID.
    Previously "" or 0 were considered as notifications

    Remove #event suffix from ID from an event response (partially fixes
    #2949) ID must be either string, int or null AND must be equal to
    request's ID. Now, because we've implemented events as responses, WS
    clients are tripping when they see Response.ID("0#event") !=
    Request.ID("0"). Implementing events as requests would require a lot
    of time (~ 2 days to completely rewrite WS client and server)

    generate unique ID for each request

    switch to integer IDs instead of "json-client-XYZ"
    id=0 method=/subscribe
    id=0 result=...
    id=1 method=/abci_query
    id=1 result=...

> send events (resulting from /subscribe) as requests+notifications (not
responses)

this will require a lot of work. probably not worth it

* rpc: generate an unique ID for each request
in conformance with JSON-RPC spec

* WSClient: check for unsolicited responses

* fix golangci warnings

* save commit

* fix errors

* remove ID from responses from subscribe
Refs #2949

* clients are safe for concurrent access

* tm-bench: switch to int ID

* fixes after my own review

* comment out sentIDs in WSClient
see commit body for the reason

* remove body.Close
it will be closed automatically

* stop ws connection outside of write/read routines
also, use t.Rate in tm-bench indexer when calculating ID

fix gocritic issues

* update swagger.yaml

* Apply suggestions from code review

* fix stylecheck and golint linter warnings

* update changelog

* update changelog2

* Add pagination to /validators

- closes #3472

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

* add swagger params, default returns all

* address pr comments

* golint fix

* swagger default change, change to default in comment

* swagger.yaml: replace x-example with example

https://swagger.io/docs/specification/adding-examples/

* Revert "swagger.yaml: replace x-example with example"

This reverts commit 9df1b006de.

* update changelog and remove extra body close

Closes #4138

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

## Issue:

    Removed BlockMeta in ResultBlock in favor of BlockId for /block
    Added block_size to BlockMeta this is reflected in /blockchain

fixes #3188

added breaking as some clients may be using header from blockmeta instead of block in /block

## Commits:

* cleanup block path

Remove duplication of data in `/block`

fixes #3188

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

* Remove duplication of data in `/block`

- Created a secondary type to be used for /block

fixes #3188

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

* remove commented out code

* fix ci

* add changelog_pending entry

* remove extra variable

* update swagger

* change int to uint for blocksize

* fix swagger

* remove extensive comments

* update changelog

* fix conflicts after merge

* use int for BlockSize and NumTxs in BlockMeta

- with 99.9% guarantee, the size of either will never reach int32
- most of the Go "Size" stdlib functions return int

* Removal of TotalTx & NumTx

- Removed totalTx and numTx

closes #2521

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

* abci proto changes

* proto number fix

* txfilter_test fix

* comments on PR

* further changes

* bring back metrics

* fix indexer

* fix TestBlockMaxDataBytes and TestBlockMaxDataBytesUnknownEvidence

* indexer service back to header

* statistics.go fix

* fix ci

* listen for blocks, not headers

to be able to record txs throughput

* fix TestNetworkNewBlock

* fix tests

* fix tests in types package

* fixes after Anton's review

* fix tests

* bring back `consensus_total_txs` metric

I mistakenly thought it was removed.

* improve changelog

* remove LastBlockTotalTx from state

* docs: remove getNumTxs from BeginBlock Java example

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

## Issue:

This PR adds an "EXISTS" condition to the event query grammar. It enables querying for the occurrence of an event without having to provide a condition for one of its attributes.

As an example, someone interested in all slashing events might currently catch them with a query such as slash.power > 0.

With this PR the event can be captured with slash.power EXISTS or just slash EXISTS to catch by event type.

## Examples:

`slash EXISTS`

## Commits:

* Add EXISTS condition to query grammar

* Gofmt files

* Move PEG instructions out of auto-generated file to prevent overwrite

* Update libs/pubsub/query/query.go

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

* Update changelog and add test case

* Merge with other changes in PR #4070

* Add EXISTS to Conditions() func

* Apply gofmt

* Addressing PR comments

* Add unsafe routes to swagger

- added `/dial_peers` & `dial_seeds` to swagger docs under unsafe tag

closes #4047

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

* address comments

* Apply suggestions from code review

* fix swagger

* docs theme

* vuepress-theme-cosmos

* version bump

* changes to docs

* more code changes

* sidebar order fix

* moar changes

* fixed dev sessions title

* fixed dev sessions title, again

* specs should show up in sidebar

* contents cards

* version bump

* sidebar, rpc

* version bump

* custom footer and super naive search

* version

* minor change to vuepress

* move swagger file

* pre and post scripts

* build

* changed docs build process

* added deployment config

* updated versions file and added deployment filters