Verifies a pubkey has signed a P2PK Proof.
The Cashu P2PK public key (hex-encoded, X-only or with 02/03 prefix).
A Cashu proof.
Optional
Optional. The message that was signed (for SIG_ALL)
True if one of the signatures is theirs, false otherwise.
Verifies a pubkey has signed a P2PK Proof.