we need to implement some sort of bridge withdrawal handler process that will:

1. watch for transfers to a specific account on the evm
2. submit a corresponding withdrawal (transfer out of bridge account) on the sequencer

this is functionally similar to the composer in that it watches a rollup and submits txs to the sequencer. however, it differs in that it watches for transfers/potentially events instead of the mempool, and it submits Transfer actions instead of Sequence actions.