refactor(mobile): immich loading overlay (#5320)

* refactor: dcm fixes

* refactor: ImmichLoadingOverlay to custom hook

* chore: dart fixes

* pr changes

* fix: process overlay add / remove in postframecallback

---------

Co-authored-by: shalong-tanwen <139912620+shalong-tanwen@users.noreply.github.com>
Co-authored-by: Alex Tran <alex.tran1502@gmail.com>

mobile/lib/shared/ui/immich_loading_indicator.dart

@@ -21,7 +21,7 @@ class ImmichLoadingIndicator extends StatelessWidget {
       padding: const EdgeInsets.all(15),
       child: const CircularProgressIndicator(
         color: Colors.white,
-        strokeWidth: 2,
+        strokeWidth: 3,
       ),
     );
   }