Add: data parameter in Window::Close method.

This allows passing data when closing a window, e.g. to indicate how it was closed.

src/depot_gui.cpp

@@ -294,7 +294,7 @@ struct DepotWindow : Window {
 		OrderBackup::Reset();
 	}
 
-	void Close() override
+	void Close([[maybe_unused]] int data = 0) override
 	{
 		CloseWindowById(WC_BUILD_VEHICLE, this->window_number);
 		CloseWindowById(GetWindowClassForVehicleType(this->type), VehicleListIdentifier(VL_DEPOT_LIST, this->type, this->owner, this->GetDepotIndex()).Pack(), false);