Support module commandline paramenter
Summary:
in prevision of more or less replacing kcmshell with systemsettings
itself, suppo loading a module as a paramenter as well as a --list
paramenter
Test Plan:
systemsettings5 kwindecoration loads the decoration kcm and the proper
category selected on the sidebar
Reviewers: Plasma, ngraham
Reviewed By: ngraham
Subscribers: broulik, bport, ngraham, plasma-devel
Tags: Plasma
Differential Revision: https://phabricator.kde.org/D29064