ui_driver: extension and modifications related to test_user
In this patch we tune login() in order to test login without
username.
Then we add edit_multivalued and undo_multivalued to test "undo"
and "reset" buttons.
Also there is a new boolean "negative" in mod_record() to switch
button assertion.
Later ssh_key methods were fine-tuned a little to add more keys,
delete all of them and to extend their usage to hosts and id views.
Lastly new method assert_value_checked() was introduced to assert
whether a particular record is checked.
https://pagure.io/freeipa/issue/7507
Reviewed-By: Petr Vobornik <pvoborni@redhat.com>