[IMP] website: add key in ir.ui.view list view if multi-websites
[IMP] website: add key in ir.ui.view list view if multi-websites

With multi-website support, the key field is more important than ever as it
kind of replace the xml_id behavior.

Thus, on the ir.ui.view list view it is usefull to see the key.

closes odoo/odoo#29419
ygol/odoo,ygol/odoo,ygol/odoo,ygol/odoo,ygol/odoo,ygol/odoo,ygol/odoo