Message Logger: removed forums load, stay smooth and cached

- Topics load fully again: the bottom-bar cleanup no longer hides the
  message list; each page fetches a full window from the server and
  answers only what the app asked for.
- Reopened chats and topics come from memory (pages, logged copies,
  downloaded media); pages are also kept on the device for restarts and
  server timeouts, with one retry before falling back.
- Media downloads run in one background queue per chat instead of
  blocking page answers or spawning a thread per page.
- The deleted badge is drawn in DialogCell.drawAvatarOverlays, under the
  avatar's own transform, so it follows the avatar through transitions;
  its paints are built once and the hot hooks skip reflection.
- Senders keep their last known profile (name, username, photo
  reference) when the app no longer has them (people.py).
- Removed chats are searchable, show "deleted chat" only in place of the
  loading subtitle, hide the join bar, order topics by activity, and
  have no unread counters.
- Uninstall takes removed chats out on the UI thread.

plugin.json

@@ -3,7 +3,7 @@
   "name": "Message Logger",
   "description": "Shows deleted and edited messages and their edit history from your telegram-panel message logger.",
   "author": "@lyuksovannyy",
-  "version": "0.1.6",
+  "version": "0.1.7",
   "icon": "exteraGramPluginIcons/4",
   "app_version": ">=12.5.1",
   "sdk_version": ">=1.4.4.3",