Apply promo code to cart and refactoring some existing features.

Apply promo code to cart and refactoring some base methods, and gift card and voucher methods.

Added

• Add features to add, remove and apply promo code to cart.
• Add method to remove invalid promo codes from cart.
• Add method to execute all existing methods of Gift Card and Voucher.

Changed

• Changes in dtos, mappers and services.
• Changes in reload method to calculate total price and apply all discount of Promo Code, Gift Card and Voucher.

assigned to @salaheddine.zidani

closed