Basic Taproot signing support for descriptor wallets

[Bushstar]

Summary

• Implements the following upstream changes.
  • https://github.com/bitcoin/bitcoin/pull/21330
  • https://github.com/bitcoin/bitcoin/commit/2478c6730a81dda3c56cb99087caf6abe49c85f5
  • https://github.com/bitcoin/bitcoin/pull/21365
  • https://github.com/bitcoin/bitcoin/pull/22934
  • https://github.com/bitcoin/bitcoin/pull/22154

Implications

• Storage

  • [ ] Database reindex required
  • [ ] Database reindex optional
  • [ ] Database reindex not required
  • [x] None

• Consensus

  • [ ] Network upgrade required
  • [ ] Includes backward compatible changes
  • [ ] Includes consensus workarounds
  • [ ] Includes consensus refactors
  • [x] None