Updates global list for storing games

lib/utility/globals.dart

@@ -1,5 +1,11 @@
 import 'package:cabo_counter/data/game_session.dart';
 
 class Globals {
-  static Map<int, GameSession> gamesMap = <int, GameSession>{};
+  /// The [gameList] contains all active game sessions.
+  static List<GameSession> gameList = [];
+
+  static void addGameSession(GameSession session) {
+    gameList.add(session);
+    gameList.sort((a, b) => b.createdAt.compareTo(a.createdAt));
+  }
 }