Use a faster method for tx containment checks

[ValarDragon]

We should use a faster method for determining if a tx is in the app-side mempool. This is too costly for recheck as it stands

The following come to mind

• Try caching the tx hashes of all txs that passed CheckTx .
  • Cache thrashing is a concern, so I think it should be done in conjunction with at minimum using a faster hash (if we can't get away with a non-cryptographic hash)
• Entirely remove the proto marshal, I don't see why we need it, given that we are taking a hash of deterministic bytes.
• Use a faster cryptographic hash (Blake3)
• Use a non-cryptographic much faster hash, and be ok with collisions (Would need analysis, so would rather try the above and see where we get)