Introduce new model of "Product Documents" to hold documents linked
to a given product template/variant, displayed on:
* quotations
* confirmed sale orders
* e-commerce product page
This will also replace the previous "Digital Files" (website_sale_digital)
logic & module, which allowed to specify product documents available
to customers after the SO invoice was paid.
This exact feature will be lost after upgrade, since we only keep the
choice to link documents on quotations/orders, but:
1) on e-commerce, carts are supposed paid when confirmed
2) on portal, the "Online Payment" settings makes sure the users
have to pay to confirm their quotation.
therefore we consider new configuration sufficient, without needing
a "paid order" choice as well.
task-3249201
Part-of: odoo/odoo#132739
Victor Feyens
5a801bc602