Issue 49381 - Refactor ACL test suite docstrings
    
    Description: We need to have properly formatted and detailed
    docstrings in all existing test suites. This commit updates ACL
    test suit docstrings.
    
    https://pagure.io/389-ds-base/issue/49381
    
    Reviewed by: Simon Pichugin
    
    Signed-off-by: Simon Pichugin <spichugi@redhat.com>