Feature/bip322 integration

[aagbotemi]

Description

This PR added BIP322 feature into BDK CLI.
It also has a usage file for testing purposes

Notes to the reviewers

Changelog notice

Checklists

All Submissions:

• I've signed all my commits
• I followed the contribution guidelines
• I ran cargo fmt and cargo clippy before committing

New Features:

• I've added docs for the new feature
• I've updated CHANGELOG.md

[notmandatory]

I'd rather not have a separate key file for this feature and try to protect it with a password and all that. This bdk-cli tool is primarily meant as a manual testing tool and example of how to use the bdk_wallet APIs so providing the public or private key descriptor via command line or environment var should also work for this signing feature.

More importantly the use of bip322 as I understand it is to be able to sign a message using what ever bitcoin descriptor script your bitcoin wallet has. If you have a private key descriptor you should be able to sign the invalid input message transaction, and if not you should still be able to create a PSBT that your hardware signers can sign. Does that make sense? Also have you seen the bdk-reserves crate? it does something similar.

[aagbotemi]

I'd rather not have a separate key file for this feature and try to protect it with a password and all that.

Still actively working on this. Will push updates once I'm done (likely within this week).