Remove ARC4 encoding (or make it optional)

[Jpja]

Remove ARC4 encoding (or make it optional)

[adamkrellenstein]

Yup I'm fine with getting rid of it. Will have some small performance benefits, it'll make composing transactions simpler, and I don't think it's necessary anymore.

However I consider it to be fundamentally unsafe to use non-Counterparty wallets to, say, trigger dispensers. You need to make sure that the address type is supported, e.g.

[jotapea]

@Jpja gets me 🤗

[jotapea]

Maybe the addition of the OP_RETURN cleartext message to the classic send of BTC can be the first step. And it could just be the 'CNTRPRTY' prefix (or the shorter 'XCP'?) by itself, without anything else in the message.

This would make much of the current #1809 unnecessary. The only consideration left would be to decide if is worth it to also have a separate create_dispense with its own message type.