[AFP-47 Shaphen Pangburn]: Do not display null praducts in page finalize percentage calculation of discount per item

Merge branch 'master' of https://gitlab.mynisum.com/ascend/ecommerce-maven into product-page-users-can-see-products-and-associated-promotion-info-for-each-item-in-main-product-page

[nmoosapet]Implememted the Cart functionality and pushing the changes to Branch

See merge request !1

[AFP-47 Shaphen Pangburn]: Add spacing and borders for each item. Add 'product no longer available' message for null products

[AFP-47 Shaphen Pangburn]: Add basic style formatting and add logic to not include null products in list display

[AFP-47 Shaphen Pangburn]: Add logic to parse and attach promos to associated products if exists and display details of that promo to client