Add support for address quotes

[staab]

Previous conversations:

#1525
#1558

It's a pretty extreme edge case, but currently address quotes are broken, because the standard way to do them is to use an a tag with a mention mark. This is ambiguous, since it collides with great-grandchild replies whose grandparent is a replaceable event referred to with an a tag. Maybe we can live with this, but since things are already broken, I think it's a nice opportunity to make address quotes work the same way as event id quotes.

Re-opening this since it had some support, even if @mikedilger's point about it being a breaking change is valid. Currently address quotes (and address replies) are undefined in the nips repo, from what I can see. FWIW, Flotilla currently uses q for address quotes.

[mikedilger]

If somebody puts a nostr: link inside a note without a matching tag (neither 'a' nor 'q') I think those render just fine, right? If I'm right, there is no need to stage this as (1) understand ['q', <address>, <relay>] first then, (2) produce them.

[staab]

Agreed, naddrs include all fields that the tag has (pubkey, relay hints). So from a render point of view, removing a tags doesn't break anything, and adding q tags doesn't improve anything.

On the query side of things, is there anyone relying on querying quotes of addressed events by a tag? This is the only thing switching to q will break. I can't imagine clients have been very consistent about tagging addresses in the first place, and querying quotes seems relatively uncommon (vs reposts).

[mikedilger]

I am just now trying to remove the creation of tags with markers. The only one I can't remove is the "a" marker because 'q' is only defined for the 'e' tag.

[staab]

Just updated this PR to remove the confusing/incorrect/impossible quote stuff from NIP 10. e-tag mentions are impossible to reconcile with e-tag quotes, as long as the positional version of NIP 10 still exists, since quotes don't exist in the reply chain.