[Cart] remove deprecated isFresh() method from CartEvent
[Cart] remove deprecated isFresh() method from CartEvent

In older versions of Sylius the cart totals were recalculated (aka the cart was "refreshed") via setting the CartEvent to fresh and checking if it is fresh on the right places. If the event was fresh, the cart was recalculated. Now that is solved via triggering the SyliusCartEvents::CART_CHANGE event. The isFresh() method is removed (it was only set, resulting in a more convoluted code, but never checked for after the switch to event listeners).

Sylius/Cart