[FIX] base: allow to give a name attribute to the res.groups copy method

Before, the name given to the copy method was always 'the old name (copy)'
(even bypassing what might have been given to the default values dict).

opw 1862214

odoo/addons/base/res/res_users.py

@@ -145,7 +145,9 @@ class Groups(models.Model):
     @api.multi
     def copy(self, default=None):
         self.ensure_one()
-        default = dict(default or {}, name=_('%s (copy)') % self.name)
+        chosen_name = default.get('name') if default else ''
+        default_name = chosen_name or _('%s (copy)') % self.name
+        default = dict(default or {}, name=default_name)
         return super(Groups, self).copy(default)
 
     @api.multi