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