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/Models/FollowersModel.swift

@@ -77,10 +77,7 @@ class FollowersModel: ObservableObject {
             
             if ev.known_kind == .contacts {
                 handle_contact_event(ev)
-            } else if ev.known_kind == .metadata {
-                process_metadata_event(events: damus_state.events, our_pubkey: damus_state.pubkey, profiles: damus_state.profiles, ev: ev)
             }
-            
         case .notice(let msg):
             print("followingmodel notice: \(msg)")