Use `Print LoadPath` for handling libnames

[JasonGross]

Nearly complete work for handling #223

Still todo:

• [ ] don't automatically add -Q . Top or w/e
• [ ] fix handling of lib_of_filename around clear_libimport_cache(lib_of_filename(output_file_name, **kwargs))
• [ ] rework lib<->filename handling to be based on pathlib more