Encrypted wallet support

Problem

Bitcoin Core wallet supports encrypting wallets using passphrase, since ord use it's rpc interface, do you guys think it's a good idea to also support this in ord? To achive this, we need to add an addition optional parameter(for example: password) to wallet create subcommand.

Pro

• It will maintain ord wallet's security even when wallet file is leaked.

Con

• When wallet is encryped, before doing any signing related operations(such as inscribe, etching, send, etc), we need to use bitcoin-cli walletpassphrase command to unlock wallet for some limited time.