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/Views/Onboarding/SuggestedUserView.swift

@@ -7,7 +7,7 @@
 
 import SwiftUI
 
-struct SuggestedUser: Codable {
+struct SuggestedUser {
     let pubkey: Pubkey
     let name: String
     let about: String

damus/Views/Onboarding/SuggestedUsersViewModel.swift

@@ -86,13 +86,7 @@ class SuggestedUsersViewModel: ObservableObject {
 
         switch nev {
         case .event(let sub_id, let ev):
-            guard sub_id == self.sub_id else {
-                return
-            }
-
-            if ev.known_kind == .metadata {
-                process_metadata_event(events: damus_state.events, our_pubkey: damus_state.pubkey, profiles: damus_state.profiles, ev: ev)
-            }
+            break
 
         case .notice(let msg):
             print("suggested user profiles notice: \(msg)")