Update our note parse to always interpret damus.io links as bech32
mentions (nostr:npub...)
This means links will get converted to nostr: on post composition, and
if we ever see a link it will also get converted to nostr: visually
Changelog-Added: Always convert damus.io links to inline mentions
Fixes: https://github.com/damus-io/damus/issues/690
William Casarin
20299615ba