[FIX] sale_stock: compute quantity differentiating incoming and outgoing pickings
[FIX] sale_stock: compute quantity differentiating incoming and outgoing pickings

Suppose that you have a SO that you deliver.
Then the client returns the products, getting a refund,
which creates an incoming picking.
If you do then update the product sold quantity, the quantity to deliver is
computed by summing the relevant picking.
We now discriminate incoming and outgoing picking, respectively substracting and
adding the quantities.

opw 1903559

closes odoo/odoo#28315
ygol/odoo,ygol/odoo,ygol/odoo,ygol/odoo,ygol/odoo,ygol/odoo,ygol/odoo