Ticket #3570: reimplement xorriso part of iso9660 listing.
When xorriso is installed, iso9660 listing was done with `xorriso .. -lsl ..`
per dir recursively. It was unbearably slow on iso images with lots of subdirs.
For example, it took my machine 2 minutes to open debian-12.5.0-amd64-DVD-1.iso
which contains 2627 dirs. This commit makes use of `xorriso .. -find / -exec
lsdl ..` instead to list the whole directory tree in a single pass.
Also, parsing of xorriso output has been reworked and as a result such
previously missing items became visible in the listing:
- symlinks
- the boot catalog file
Closes MidnightCommander/mc#196.
Signed-off-by: Andrew Borodin <aborodin@vmail.ru>