DEVDOCS-5671 [revise] Checkout Storefront, Update gift wrapping around CRUD

[bc-tgomez]

DEVDOCS-5671

What changed?

• Add Gift Card schema to Storefront Checkout endpoints from PR# 1536

PR Comments

we can assign a giftWrapping to lineItems using the Storefront API
POST /api/storefront/carts
POST /api/storefront/carts/{cartId}/items
we can update an existing giftWrapping using the Storefront API
PUT /api/storefront/carts/{cartId}/items/{itemId}
PUT /api/storefront/checkouts/{checkoutId}/carts/{cartId}/items/{itemId}
we can delete an existing giftWrapping using Storefront API (pass giftWrapping: null). if we don't pass giftWrapping, DO NOT CHANGE CURRENT STATUS
PUT /api/storefront/carts/{cartId}/items/{itemId}
PUT /api/storefront/checkouts/{checkoutId}/carts/{cartId}/items/{itemId}

Anything else?

PR#1536

ping @bc-shawnwang @valentindellangela