[R4R]support Index service recovery and indexHeight in Status api

[unclezoro]

Description

1. Will recover index data from restart or crash
2. Add field--'indexHeight' to status api.
3. Add indexHegiht metrics.

Rationale

This pr have pass though following testcases:

1. Upgrade from old binary, no recover will do. checked
2. If previous do not use index and now change to use index, no recover will do. checked
3. If index data lost, will recover. checked
4. If data have indexed, but did't write the height, redo index have no side effect. checked
5. Rpc api have changed. checked
6. Metrics have changed. checked
7. write to statedb will not cause consensus issue. checked

Example

api of 'Status ' changed:

{
"jsonrpc": "2.0",
"id": "",
"result": {
...
"sync_info": {
  		"latest_block_hash": "F51538DA498299F4C57AC8162AAFA0254CE08286",
  		"latest_app_hash": "0000000000000000",
  		"latest_block_height": "18",
  		"latest_block_time": "2018-09-17T11:42:19.149920551Z",
  		"catching_up": false,
  		"index_height": "18"
  	},
...
}

Changes

Preflight checks

• build passed (make build)
• tests passed (make test)

Already reviewed by

...

Related issues

@xzjcool @Kaiqiang all other sdk need change the 'status' api response.

[rickyyangz]

as discussed, please check whether it has any performance impact in high tps

[rickyyangz]

remember to fix the state_recover tool

[unclezoro]

sure