Support for ending battles when only one side has creatures that are available for battle.

src/Battling/Models/Creature.hpp

@@ -69,6 +69,7 @@ namespace CreatureLib::Battling {
         void SetBattleData(Battle* battle, BattleSide* side);
         Battle* GetBattle() const;
         BattleSide* GetBattleSide() const;
+        void SetOnBattleField(bool value) {_onBattleField = value;}
         bool IsOnBattleField() const { return _onBattleField; }
 
         const std::string& GetNickname() const;