Checkout

As with AddCartItem, this is used in AddCartItemRequest - same as Checkoutrequest, but without the SessionToken, we convert this to AddCartItemRequest in the controller

Name	Description	Type	Additional information
Pin	Not yet implemeted - validates against the guests's chosen pin number	string
Comment		string
NumberOfGuests		integer
DeliveryDateTime		date
IsDeliveryDateTimeUtc		boolean
Total		decimal number