CSR UI: Add line item (Beta)

Description

The Customer Service screen lets your order support team quickly identify and then perform common tasks on shopping carts. For example, you can add or remove line items as well as update their quantity. To navigate to the Customer Service screen, from the Commence main menu, click Customer Service.
To access this feature, the user must be a member of the EPiBetaUsers role. For more information, see https://world.episerver.com/documentation/Items/Installation-Instructions/beta-features/ and https://world.episerver.com/documentation/developer-guides/commerce/orders/customer-service/csr-ui/.