Support for failing an AttackTurnChoice.

This is handled before the actual ExecutingAttack is created, so allows for failing a move a lot earlier than before.

src/Battling/Flow/TurnHandler.cpp

@@ -134,6 +134,11 @@ void TurnHandler::ExecuteAttackChoice(const ArbUt::BorrowedPtr<AttackTurnChoice>
         return;
     }
 
+    if (choice->HasFailed()) {
+        FAIL_HANDLING_NO_TARGET(choice, choice->GetUser());
+        return;
+    }
+
     auto* attack = attackScoped.TakeOwnership();
     battle.GetValue()->TriggerEventListener<AttackUseEvent>(attack);
     battle.GetValue()->RegisterHistoryElement<AttackUseHistory>(attack);