Replace QueryConsensusStates with QueryConsensusStateHeights

[adizere]

Depends on cosmos/ibc-go#798

See cosmos/ibc-go#798 (comment)

[adizere]

Re-prioritised this feature as a request from the IBC-go team. The context is as follows:

• misbehaviour handling relies on QueryConsensusStatesRequest which is expensive, hence we disabled that feature by default
• misbehaviour handling is "important for security", so we should enable it by default
  • https://github.com/informalsystems/hermes/blob/v1.1.0/config.toml#L27
• the linked PR in IBC-go Add a gRPC endpoint for fetching consensus state heights cosmos/ibc-go#798 allows us to replace QueryConsensusStatesRequest with a lightweight alternative that fetches only the header heights, hence we can reduce the pressure on full nodes, allowing us to safely (without major side-effects like pressure on nodes) re-enable misbehaviour by default