feat(grants): rename permission & _add_grant update description

* Added rename/rename_all/rename_clone grants.
* Added new feature when _add_grant(x, x, x, $description) is different from the BD updates it.
* added function to the conditions "can_manage_machine", "is_operator", "can_list_clones" and "can_list_machines".
* simple test checking the listing with rename_all and rename_clone
* simple test for rename
* major fix on SQL error _add_grant

issue #996