[CI] Update and rename mld parsing script to scripts/parse_xml_report.py

The MLD parsing scripts does more than MLD parsing, so it is renamed to scripts/parse_xml_report.py. There is now an optional summary output in the form of a histogram in a separate .csv file.

The optional report is not used in the BASOP CI currently, so that change will not affect the scripts. However, the renaming of the script would need to be done on all branches in the BASOP that require CI testing. Maybe it would be better not to rename the script, even though the name is a little bit wrong. @kiene, what do you think?