[FIX] point_of_sale: Add sales description to pos invoice

Current behavior:
If you add a sale description to a product, it will not be added to the
invoice created from the PoS.

Steps to reproduce:
- Add a sale description to a product
- Create a PoS order with this product
- Create an invoice from the PoS order
- The sale description is not added to the invoice

opw-3221481

closes odoo/odoo#117974

Signed-off-by: Joseph Caburnay (jcb) <jcb@odoo.com>