Storefront API Cart BXGY discount line folding

API

As of today, the way cart lines are folded when a BXGY discount is applied to the cart is changing in the Storefront API. The lines will now be grouped by applied discount and discounted amount. This change ensures that the Storefront API behaviour matches the existing line folding functionality of the Online Store/Ajax API Cart.

For example, if you have a buy one get one free discount for a product variant and you add 3 of that variant to a cart. The cart lines will be; * Item with quantity of 1, no discount applied * Item with quantity of 1, BXGY discount code applied, adjusted discounted price of 0 * Item with quantity of 1, BXGY discount code applied, full price of product variant

This change reflects the existing line folding functionality of the Online Store/Ajax API Cart.