[Feature request] Add the capability to mix to PayNyms

[4rkad]

Some time ago I was talking with Craig about the option of using the MIX TO feature to send funds to friends or partners. I've been doing it for a while, and it's a game-changer, especially for partners who receive Bitcoin for their businesses. They can enter a tx0 and then distribute funds that way. Here's an example:

https://x.com/Multicripto/status/1622956145513058305

You could even swap from on-chain to LN in robosats this way, also without cost.

You can also use the xpub you obtain on Bisq to send directly from Whirlpool.

Craig also mentioned the possibility of including the ability to use MIX TO to send to a Paynym. What would be the usefulness of this feature? Imagine that companies like Bitrefill and Thebitcoincompany enable the option to receive via Paynym. The user could use the MIX TO PAYNYM option to send directly and at no cost from Whirlpool. You would just need to initially make a notification tx to link with the paynym.

[rapidlab309]

Great idea. Would love to see it!