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

src/Battling/Models/BattleSide.cpp

@@ -37,8 +37,13 @@ void BattleSide::SetChoice(BaseTurnChoice* choice) {
 }
 
 void BattleSide::SetCreature(Creature* creature, uint8_t index) {
+    auto old = _creatures[index];
+    if (old != nullptr){
+        old->SetOnBattleField(false);
+    }
     _creatures[index] = creature;
     creature->SetBattleData(_battle, this);
+    creature->SetOnBattleField(true);
 }
 
 bool BattleSide::CreatureOnSide(const Creature* creature) const {