Legger til enum for vinnsenario

Co-Authored-By: torlunjen <torlunjen@users.noreply.github.com>

src/main/java/inf112/fiasko/roborally/element_properties/GameState.java

@@ -16,5 +16,7 @@ public enum GameState {
     //Indicates that the user is in the process of choosing whether to power down
     CHOOSING_POWER_DOWN,
     //Indicates that the user is in the process of choosing whether to stay in power down
-    CHOOSING_STAY_IN_POWER_DOWN
+    CHOOSING_STAY_IN_POWER_DOWN,
+    //Indicates that the game is won by a player
+    GAME_IS_WON
 }