psbt: handle unspendable psbts

Summary:

• Have a PSBTAnalysis state that indicates invalid PSBT

Invalid PSBTs need to be re-created, so the next role is the
Creator (new PSBTRole). Additionally, we need to know what went
wrong so an error field was added to PSBTAnalysis.

A PSBTAnalysis indicating invalid will have empty everything,
next will be set to PSBTRole::CREATOR, and an error message.

• Mark PSBTs spending unspendable outputs as invalid in analysis

This is a backport of Core PR17524

Test Plan:

ninja all check-all

Reviewers: #bitcoin_abc, Fabien

Reviewed By: #bitcoin_abc, Fabien

Differential Revision: https://reviews.bitcoinabc.org/D8065