Add default implementation for OnBeforeTurn script hook.

src/Battling/ScriptHandling/Script.hpp

@@ -24,7 +24,7 @@ namespace CreatureLib::Battling{
             return _name;
         }
 
-        virtual void OnBeforeTurn(const BaseTurnChoice* choice);
+        virtual void OnBeforeTurn(const BaseTurnChoice* choice){};
         virtual void FailIncomingAttack(ExecutingAttack* attack, Creature* target, bool& result){};
         virtual void IsInvulnerable(ExecutingAttack* attack, Creature* target , bool& result){};
         virtual void OnAttackMiss(ExecutingAttack* attack, Creature* target){};