[FIX] sale: show discount in portal
[FIX] sale: show discount in portal

Before this commit, discount was never displayed in the portal.
So if you bought 1 iPad at 1800$ with 50% you see in your poral:

Product         Unit P.  Qty  Subtotal
[photo] Ipad    $1800    1.0      $900

Now, similarly to the report pdf, we show discount if at least
one line contains a discount.

This commit closes #11305

ygol/odoo,ygol/odoo,ygol/odoo,ygol/odoo,ygol/odoo,ygol/odoo,ygol/odoo