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/ZapsModel.swift

@@ -37,7 +37,8 @@ class ZapsModel: ObservableObject {
     func unsubscribe() {
         state.pool.unsubscribe(sub_id: zaps_subid)
     }
-    
+
+    @MainActor
     func handle_event(relay_id: String, conn_ev: NostrConnectionEvent) {
         guard case .nostr_event(let resp) = conn_ev else {
             return