Create a custom query route for tendermint to use to create transaction inclusion proofs

[evan-forbes]

Currently, when creating a tx inclusion proof in celestia-core, we have to encode a portion of the block data into rows. This is necessary to create the nmt tree(s) used to create the proof(s). It's problematic not only because we don't want to have any application logic in core, but in order to fully test that code we have to have a lot of other application specific logic (malleated txs, non-interactive defaults/other square layout rules).

To fix this, we'd like to move all share encoding logic to the app, but this means we can't do tx inclusion proofs in core like normal tendermint. We can get around this by creating a custom query route, and calling that route each time we want to create a tx inclusion proof in tendermint.

This will involve:

• Move the prove pkg from core to app #699
• feat: Implement and install new ABCI Query for transaction inclusion proofs  #708
• Use the custom ABCI Query route to create transaction inclusion proofs celestia-core#851