Allow fee-bumping transactions

Commit, reveal, and send transactions can all get stuck in the mempool. The wallet opts them into RBF, so they can be bumped, but we don't have any code to actually bump them. We should add this.

First step is a design. Does ord wallet bump TXID work? that would be the simplest design, but if ord needs to do different things for commit, reveal, and send transactions, it would have to figure out which TXID was. Another option is ord wallet rescue TXID, which will fee bump, not reveal inscriptions, and return the UTXO to your wallet to try again with a higher fee. If this is really simple, we might consider prioritizing it.