refactor: remove offline indicator and streamline chat page logic

- Deleted the OfflineIndicator widget and its associated logic to simplify the codebase.
- Removed offline checks from the ChatPage, enhancing performance and reducing unnecessary rebuilds.
- Adjusted the ChatsDrawer to change icon size for better visual consistency.
- Cleaned up unused imports related to offline handling across multiple files.

lib/features/navigation/widgets/chats_drawer.dart

@@ -1406,7 +1406,7 @@ class _ChatsDrawerState extends ConsumerState<ChatsDrawer> {
                           ? CupertinoIcons.settings
                           : Icons.settings_rounded,
                       color: theme.iconSecondary,
-                      size: IconSize.small,
+                      size: IconSize.medium,
                     ),
                   ),
                 ],