Handle clear cart button

[kgonella]

In case of the customer use the clear button, the removeFromCart event should be sended for all product that were in the cart.

[stefandoorn]

Isn't Sylius already internally sending the cart remove event multiple times? If not, that would be good anyway in Sylius I think.

[kgonella]

I don't think so. Single item add or remove events are dispached in the OrderItemController.
The clear is done in the OrderController::clear() Action. It dispached the remove event on the order directly.

[stefandoorn]

@kgonella Would you be able to submit a PR? :-) I think with the current GA4 and mainly backend listeners, it should be easier than it used to be with frontend tracking.