feat: Add sign method for psbt

[ItoroD]

Description

Addresses #866

Notes to the reviewers

See comment - #866 (comment)

Documentation

• bdk_wallet
• bitcoin
• uniffi
• Other:

Changelog

Checklists

All Submissions:

• I've signed all my commits
• I followed the contribution guidelines
• I ran cargo fmt and cargo clippy before committing
• I've added exactly one changelog:* label
• I've linked the relevant upstream docs or specs above

New Features:

• I've added tests for the new feature
• I've added docs for the new feature

[ItoroD]

This file should be removed.

[ItoroD]

Just did a rebase on this one and I see errors. Because I am changing the structure of keymap in this PR any other PR that makes use of keymap will cause this PR to fail after rebase. I will fix this and alert you when its done.

But we might want to consider reviewing this and merging this soon, to reduce the number of iterations. Or I fix it when we are almost ready for it.

[reez]

Just did a rebase on this one and I see errors. Because I am changing the structure of keymap in this PR any other PR that makes use of keymap will cause this PR to fail after rebase. I will fix this and alert you when its done.

But we might want to consider reviewing this and merging this soon, to reduce the number of iterations. Or I fix it when we are almost ready for it.

yeah feel free to just ping me here when it gets un-drafted so I can try to review it

[reez]

Shaping up nice, a couple questions:
-Psbt::sign currently discards rust-bitcoin’s signing result and always returns Ok, is that intended?
-Should we keep KeyMap opaque and construct miniscript’s KeyMapWrapper internally so consumers get the direct psbt.sign(keyMap) workflow discussed in 866?

[ItoroD]

-Should we keep KeyMap opaque and construct miniscript’s KeyMapWrapper internally so consumers get the direct psbt.sign(keyMap) workflow discussed in 866?

Yes, I agree. Theres nothing else users are using the wrapper for. I will update to reflect this.

Psbt::sign currently discards rust-bitcoin’s signing result and always returns Ok, is that intended?

No, that was not intended. At the very least error should be return if error (I guess I got too excited once i saw sign worked 😂). But I did intentionally discard the rust-bitcoins result. Just like keymapwrapper, do our users have use for SigningKeysMap (rust-bitcoin’s signing result) I was not sure.

[ItoroD]

Updated error message