[backport#13932] Figure out what is missing during signing

Summary:
When signing an input, figure out what was requested for but was unable
to be found and store it in a SignatureData.

Return this information in SignPSBTInput.

https://github.com/bitcoin/bitcoin/pull/13932/commits/cb40b3abd4514361a024a1e7a1a281da9261261b

Depends on D6045

This is a partial backport of Core PR13932

Test Plan:

ninja check check-functional

Reviewers: #bitcoin_abc, deadalnix, nakihito

Reviewed By: #bitcoin_abc, deadalnix, nakihito

Subscribers: nakihito, deadalnix

Differential Revision: https://reviews.bitcoinabc.org/D6046