This commit makes two major things:
1. Move the product catalog from `sale` to `product`.
It moves the product catalog's code from `sale` to `product` module in
order to be able to use it in other modules.
A mixin, `product.catalog.mixin`, was created for to make other models
catalog compatible.
2. It enables the product's catalog in `purchase`.
In `purchase`, the catalog differs a little bit from `sale`:
- If Unit of Measure is enable, the UoM for each product will appear in
the catalog;
- If the product purchase's UoM or the purchase order line's UoM is
different than the default product's UoM, the former one will be
displayed (in bold so the user can know it's the UoM to refer);
- When opening the product's catalog from a purchase order, the products
will be filtered by the PO's vendor;
- Some data from the vendor list will be used if appliant: the minimum
quantity and the price;
- If there is at least one product's packaging, a button will be
displayed to increase the qty by the packaging's one. If a packaging
is set on the purchase order line, this one will be used.
task-3373589
Part-of: odoo/odoo#135502
svs-odoo
bc01c7bcec