BlockResults rpc has changed in comet v0.38 update

[colin-axner]

v0.34.X Block Results RPC:

// ABCI results from a block
type ResultBlockResults struct {
	Height                int64                     `json:"height"`
	TxsResults            []*abci.ResponseDeliverTx `json:"txs_results"`
	BeginBlockEvents      []abci.Event              `json:"begin_block_events"`
	EndBlockEvents        []abci.Event              `json:"end_block_events"`
	ValidatorUpdates      []abci.ValidatorUpdate    `json:"validator_updates"`
	ConsensusParamUpdates *abci.ConsensusParams     `json:"consensus_param_updates"`
}

v0.38.X Block Results RPC:

// ABCI results from a block
type ResultBlockResults struct {
	Height                int64                     `json:"height"`
	TxsResults            []*abci.ExecTxResult      `json:"txs_results"`
	FinalizeBlockEvents   []abci.Event              `json:"finalize_block_events"`
	ValidatorUpdates      []abci.ValidatorUpdate    `json:"validator_updates"`
	ConsensusParamUpdates *cmtproto.ConsensusParams `json:"consensus_param_updates"`
	AppHash               []byte                    `json:"app_hash"`
}

The relayer currently looks for begin and end blocks here after performing this rpc query

This results in no begin/end block results for chains on SDK v0.50

Begin/End block event parsing is needed for interchain accounts integration with gov/groups SDK modules

[jtieri]

This was addressed in #1312 by maintaining a fork of cometbft before v0.38.0 and importing that fork as well. It seems like cometbft will soon have a stable v1.0.0 release, at that point we should be able to drop the fork entirely as well.