nostrdb: add profiles to nostrdb

This adds profiles to nostrdb

- Remove in-memory Profiles caches, nostrdb is as fast as an in-memory cache
- Remove ProfileDatabase and just use nostrdb directly

Changelog-Changed: Use nostrdb for profiles

damus/Components/Status/UserStatusSheet.swift

@@ -136,6 +136,6 @@ struct UserStatusSheet: View {
 
 struct UserStatusSheet_Previews: PreviewProvider {
     static var previews: some View {
-        UserStatusSheet(postbox: PostBox(pool: RelayPool()), keypair: Keypair(pubkey: .empty, privkey: nil), status: .init())
+        UserStatusSheet(postbox: PostBox(pool: RelayPool(ndb: .empty)), keypair: Keypair(pubkey: .empty, privkey: nil), status: .init())
     }
 }