Test importing descriptors with key origin information and add release notes

Summary:
Test is separated from the rest of the changes to make review easier.

Partial backport of Core PR14021
https://github.com/bitcoin/bitcoin/pull/14021/commits/4c75a69f36a7630342e68b12999115e6b6b1e1e0
https://github.com/bitcoin/bitcoin/pull/14021/commits/cb3511b9d5f3d8a86e090ebed5a4aeaf758430b8

Depends on D6230

Test Plan:

ninja
ninja check
ninja check-functional

Reviewers: O1 Bitcoin ABC, #bitcoin_abc, deadalnix

Reviewed By: O1 Bitcoin ABC, #bitcoin_abc, deadalnix

Differential Revision: https://reviews.bitcoinabc.org/D6215