Preserve the natural order in ISO9660 archives for linked files (#1974)

Preserve the natural order in ISO9660 archives for linked files (#1974)

When an ISO9660 archive contains hard links or sym links, the order of
the files in the output of 'bsdtar -tf filename' is not the natural
order.

With an extension to the key (while still supporting ISO files up to 2^48
bytes) the sorting order is guaranteed for ISO files that contain linked
files for up to 2^16 files in total.

Co-authored-by: Martin Matuska <martin@matuska.de>