Create a Consignment

Adds a new *Consignment* to *Checkout*. Perform the following two steps to define the fulfillment of the items in the cart. ### For **shipping** consignments: 1. Add a new Consignment to Checkout. * Send a `POST` request to `/consignments` with each shipping address, line item IDs, and quantities. Each address can have its own line item IDs. * Provide a full valid customer address before placing the order. If provided, the order placement will succeed. * As par...