The moc process already rebuilds the plugin when the JSON file changes, consequently the additional parameter is not needed.
Task: https://phabricator.kde.org/T14649
KScreenLocker does not allow unlocking the screen via the screensaver interface by design (https://bugs.kde.org/show_bug.cgi?id=425616).
However it allows to do it via the logind interface, so let's use that here.
While at it also refactor the code and properly track and send the state, so the other device can show an appropriate label.
This automatizes the generation of logging categories so a
kdeconnect-kde.categories is generated and installed to
/usr/share/qlogging-categories5/ so kdebugsettings can use it.
Also, sets the default logging level to Warning. So now the logs
of users won't be filled with debug messages but they can
modify the configuration easily with kdebugsettings.
