069d2fd07e Add XOnlyPublicKey support for PSBT key retrieval and improve Taproot signing (Erick Cestari)
Pull request description:
The `bip32_sign_schnorr` function was previously only attempting to retrieve private keys using `KeyRequest::Bip32`, which limited the ability to sign Taproot inputs with key maps that don't support BIP32 derivation paths.
## Changes
- Added new `KeyRequest::XOnlyPubkey` variant to support direct retrieval using XOnly public keys
- Implemented `GetKey` for `HashMap<XOnlyPublicKey, PrivateKey>` for more efficient Taproot key management
- Modified `HashMap<PublicKey, PrivateKey>` implementation to handle XOnlyPublicKey requests by checking both even and odd parity variants
- Added comprehensive tests for both key map implementations
These improvements enable wallet implementations to store keys indexed by either `PublicKey` or `XOnlyPublicKey` and successfully sign PSBTs.
Closes#4150
ACKs for top commit:
Kixunil:
ACK 069d2fd07e
apoelstra:
ACK 069d2fd07e7d6dad1401fce6ab28ab1dc9f3c60f; successfully ran local tests
Tree-SHA512: 0ae07309b772f1a53e7da45073f7e2337cc332ab2335925d623d0e1ad1503aab77673bbbd64e5533ae7fc8d57f3577db0ae7ac3b05279de92d3b34ab8eeae90f
87889955f9