BIP352: PSBT support

The updated draft for the Bitcoin Improvement Proposal (BIP) has undergone significant modifications, as detailed in the latest version available at this link. A noteworthy change is the elimination of the OutputGenerator role from the proposal. This modification aligns with a shift towards employing the Elliptic Curve Diffie-Hellman (ECDH) share technique, a method highlighted by @josibake. The adoption of the ECDH share technique enhances the security and efficiency of the proposed improvements.