orders: allow matching with special requirements (anchor commitments etc.)

[cryptagoras]

As a seller/maker one issue that varies the experience of selling a channel lease is if the buyer will stay online or for whatever reason making me force close the channel which usually results in non-trivial economic damage.

Anchor channels provide a serious improvement on these cases, so as a seller I would like to be able to specify that I'm selling only anchor channel leases.

This will provide a greater peace of mind and allow me to provide better offers without having to account for potentially costly force-closings.

(I know this is probably too niche and hopefully anchors will get adopted faster enough, but maybe keep it in mind :clinking_glasses: )

[Roasbeef]

Def, this is in the works as an explicit order type. Needs a small change to lnd that makes channel types explicit: https://github.com/lightningnetwork/lnd/pull/5071

[guggero]

Going through the older issues, I noticed this was fixed by https://github.com/lightninglabs/pool/pull/300.