* Switch to using org.kicad.kicad as the main app ID
* Move the appstream file to a metainfo file
* Rename all metadata files to use the reverse DNS scheme
* Add header matching to mime type files where possible
* Add a mime type for gerber job files
* Add a QA test that verifies all the linux metadata files and
run it in CI
* Update the visible names in the launcher entries to be more
consistent with the internal visible names
* Update various strings and items in the metainfo file so they
are more descriptive and easier to read
This is important, because it affects the ordering of entries in .pot and
.po files. Most existing files are in alphabetic order already, so this
should minimize diffs.
It must not be included in translations, because it contains files for
tests and/or for future development (mainly new Eeschema lib code) and
are therefore not used actively in Kicad code.