[Add] End game, Restart, Final Check

Assets/Runtime/Core/GameStateService.cs

@@ -18,5 +18,10 @@ namespace Minesweeper.Core
             Current = state;
             StateChanged?.Invoke(Current);
         }
+
+        public void NotifyCurrentStateChanged()
+        {
+            StateChanged?.Invoke(Current);
+        }
     }
 }

Assets/Runtime/Core/IGameStateService.cs

@@ -9,5 +9,6 @@ namespace Minesweeper.Core
         GameState Current { get; }
 
         void SetState(GameState state);
+        void NotifyCurrentStateChanged();
     }
 }