[FIX] account, usabilty: add form mode to action open.

This fix allows users to view the form of the invoices they accessed through the payments (via the 'invoices' button)

addons/account/models/account_payment.py

@@ -282,7 +282,7 @@ class account_payment(models.Model):
         return {
             'name': _('Paid Invoices'),
             'view_type': 'form',
-            'view_mode': 'tree',
+            'view_mode': 'tree,form',
             'res_model': 'account.invoice',
             'view_id': False,
             'type': 'ir.actions.act_window',