outsource drawer context in seperate files

lib/video_screen/videoscreen.dart

@@ -3,7 +3,7 @@ import 'package:flutter/material.dart';
 
 import '../api/token.dart';
 import '../api/video_api.dart';
-import '../platform.dart';
+import '../utils/platform.dart';
 import '../screen_loading.dart';
 import '../types/video.dart';
 import '../types/video_data.dart';