Feature Request [privacy]: Add support for BIP-352 Silent Payments

### Description

Privacy on bitcoin blockchain is desperately needed, growing day by day. The newest proposal for achieving such thing is [BIP-352 Silent Payments](https://github.com/bitcoin/bips/blob/master/bip-0352.mediawiki), by creating a static reusable payment code, which others can use to generate brand new fresh address every time when sending bitcoin to the recipient.

I'm requesting adding support for this feature, to widen the adoption of privacy option on bitcoin.

Following couple of FOSS demo apps, major player Cake Wallet added this feature recently and I would like for Green, as a standard for many, to adopt this too.