New "Cart Mode" for Multi-recipient checkout

Multi-recipient checkout updates

• Multi-recipient checkout now works with items in the user's cart. Now, when the "Multi Recipient Checkout" app block is added to a collection template, it will display collection products. When added to any other template, it will display the products in the cart.

• Added a "Multi Checkout Button" app block, to easily link from the cart to the multi-recipient checkout page

• Added address suggestions and autocomplete

• In the shipping schedule rules, you can now set rules by product, with different availability dates by product, tag, collection, etc