Rework sequencer logic around CheckTx and transaction execution

[Fraser999]

We currently are too permissive in our CheckTx flow, allowing txs into the CometBFT and appside mempools which will subsequently fail execution via stateful checks in the check_and_execute flow.

This is problematic as such txs are not recorded in the sequencer block nor in the CometBFT txs. This means they remain present in the mempools of all but the validator proposing the block for that round.

We need to rework this so that such txs either fail during CheckTx (meaning they never enter mempools), or that execution failures are recorded rather than being skipped, meaning all sequencers (validators and full nodes) are able to remove such failed txs from their mempools. Potentially a combination of both approaches will prove to be the best solution.