Swap in descriptors support into scantxoutset

Summary:
This is a partial backport of Core PR13697 : https://github.com/bitcoin/bitcoin/pull/13697/commits/151600bb4972f7bab4ed4a03d1f67c38e081fefe

Also includes:

• [QA] Add xpub range tests in scantxoutset tests https://github.com/bitcoin/bitcoin/pull/13697/commits/1af237faefc316bd708e25d6901ee6f17b706e57
• Add experimental warning to scantxoutset https://github.com/bitcoin/bitcoin/pull/13697/commits/fddea672eb8f63012f2e9ce04fa477e5d4140750
• [QA] Extend tests to more combinations https://github.com/bitcoin/bitcoin/pull/13697/commits/6495849bfd362d6a2f128bac5982fa9e3e2e3396
• Support h instead of ' in hardened descriptor paths https://github.com/bitcoin/bitcoin/pull/13697/commits/f6b7fc349ccf9cfbeb7e91e19c20e2a2fcc9026f

Depends on D4357 and D4420

Test Plan:

make check
./test/functional/test_runner.py

Reviewers: #bitcoin_abc, Fabien

Reviewed By: #bitcoin_abc, Fabien

Subscribers: Fabien

Differential Revision: https://reviews.bitcoinabc.org/D4421