allow for user-deposit mode (for both XMR and ETH)
currently, the swap daemon requires either private key or wallet access to funds, as it automatically locks funds for you. for the eth side, it requires a private key and for the monero side it requires an unlocked wallet on monero-wallet-rpc. 

while this makes the swap experience nicer in some ways as it doesn't require user interaction during the swap, it's not as condusive of an experience within a UI, as it requires the user to run the daemon on the backend and load their keys into it. for a completely in-browser experience, the user would need to interact during the swap by locking funds.

this issue is to implement a mode (specified by a CLI flag) that does not require private keys or wallet access, but instead prompts the user to send funds to some address during the locking stage.