Updated multi-products

Multi-products will be rewritten so that they will be easier to manage and create in the back office and that there will be support for certain functions that are missing in the checkout:

• Ability to have multiple multi-products on the same line in the checkout, today they are put on a separate line

• Possibility to split a multi-product for when the guest should pay a certain part

• Ability to put kitchen messages on the sub-products