QueryCountStatsMonitor doesn't track sql query metrics

QueryCountStatsMonitor provides the following query metrics
- `query/count`
- `query/success/count`
- `query/failed/count`
- `query/interrupted/count`
- `query/timeout/count`

It looks like these metrics don't track the sql queries invoked against the `druid/v2/sql` endpoint.

This could be because the Broker is tied to `BrokerQueryResource` as the `QueryCountStatsProvider` implementation and even if `SqlResource` implements `QueryCountStatsProvider`, it wouldn't work. Unless the `SqlResource` was isolated as such for a specific reason, I'd like to check the feasibility of merging `SqlResource` into `QueryResource` so that `druid/v2/sql` can take advantage of the query count stats monitoring within `QueryResource`.

@jihoonson Any thoughts on this?

Start by reading BrokerQueryResource, SqlResource, QueryResource, and QueryCountStatsProvider to trace how the Broker selects its query-count implementation for druid/v2/sql. Compare the resource wiring and determine whether SQL requests can use the existing monitoring path; done means the query, success, failed, interrupted, and timeout metrics track SQL endpoint requests, with coverage for that behavior.

Written by the indexing model from the issue text.