* rpc: implement the ADR 075 /events method (#7965)
This method implements the eventlog extension interface to expose ABCI metadata
to the log for query processing. Only the types that have ABCI events need to
implement this.
- Add an event log to the environment
- Add a sketch of the handler method
- Add an /events RPCFunc to the route map
- Implement query logic
- Subscribe to pubsub if confingured, handle termination
* add MatchesEvents test
* add TODO due to backport sequence
Co-authored-by: M. J. Fromberger <fromberger@interchain.io>
d47b675cda