refactor: v50-ify

[Reecepbcups]

Tasks:

• Get all basics to compile
• Upstream SDK work (as MINIMAL as possible, pull anything app side that we can)
• Build simapp with spawn EPIC: Spawn should ETH spawn#183
• Get a basic test showcasing ERC20 <-> Bank works
• Use that app to finish unit test
• interchaintest cosmos+evm chain type

Requirements

Must replace your go.mod to a cosmos-sdk fork for some EVM specifics

[Reecepbcups]

I need to verify that

// get block headers after a certain cursor. Can use an empty string cursor
// to get the latest block header.
func (a *FilterAPI) getBlockHeadersAfter(
	ctx context.Context,
	cursor string,
) ([]common.Hash, string, error) {
	q := NewBlockQueryBuilder()
	builtQuery := q.Build() // TODO: verify this is a good query

channel subscription works as expected. This is the largest impl diff since they had their own custom reader client. The TM event names may be changed for v50 and/or the subscribe channel logic may be off.

It just needs to query a said block to get the hash from consensus. not sure if the Subscribe will work for that. May have to add more.