Publish product prices only, Products can be added to a cart by SKU

It is now possible to publish only the prices of a product. This allows you to keep other product information you don't want to publish yet, like updates in the product description, in staged projection while the updated prices will be published already. Product variants to be added to a cart can now be specified by their SKU. Before, the only option was to specify them by their product ID plus variant ID.

• [API] The Product publish update action has a new field scope controlling the publishing behavior. By default this scope is set to "All", but when set to "Prices" only the prices will be published.
• [API ]The ProductPublishMessage also has a new field scope, containing the scope that was set during the corresponding publish update action.
• [API] The LineItemDraft Product Variant identification has been added to be able to add a product to a cart by SKU, either when creating the cart, or when adding a line item.