Add ComicInfo.xml and CoMet parsing.

One is the format used by ComicRack(and since then, others),
and the other an open 'standard'.

Both get loaded into the ACBF data, while side features, like comments,
notes, currentpage, etc, get loaded into the KFileMeta. This should
help with switching to use Peruse when having libraries using these formats.

Had also wanted to support ComicBookInfo, but that is stored as JSON inside
the zip comment field, and I can't figure out how to get KArchive to read that
value.

Differential Revision: https://phabricator.kde.org/D15601