* Don't use getattr in _get_parent_attribute to avoid recursion issues
Fixes#23609
* Move extend/prepend to field attribute
Also removes _get_attr* methods that were basically just calling
_get_parent_attribute because it needed to set those params.
Also modifies _get_parent_attribute() to pull those values from the
FieldAttributes instead of using the ones passed into the function.
* Better fixes for _get_parent_attribute
* Reimplement iso_extract using 7zip (not requiring root)
So one of the drawbacks of the original implementation is that it required root for mounting/unmount the ISO image.
This is now no longer needed as we use 7zip for extracting files from the ISO.
* Fall back to using mount/umount if 7zip not found
As discussed with others.
Also improved integration tests.
A preliminary set of test targets for "core" supported module that had no independent tests. These will also help us ensure python3 compatibility for those modules and prevent future regressions.