RPC client incompatibility with Tendermint 0.32 /block_results endpoint

[Devashish Dixit]

In tendermint/tendermint#3643, tags were changed to events (event now have an event_type and a list of tags). This change will affect RPC calls such as /block_results (https://github.com/tendermint/kms/blob/master/tendermint-rs/src/abci/responses.rs#L71).

[Tony Arcieri]

Moving this to informalsystems/tendermint-rs#4