Improve file descriptor xml output, add fd and path elements
Add needs_xml_output to none tool so it can also output xml when
--track-fds enabled.
Use xml protocolversion 5 when clo_track_fds is enabled
Split OpenFD pathname and description. Add description when a file
descriptor is closed so it can be used in a future error. On error
print <fd> element and (if known) a <path> element.
Add docs/internals/xml-output-protocol5.txt.
https://bugs.kde.org/show_bug.cgi?id=328563
Co-Authored-By: Mark Wielaard <mark@klomp.org>