Make use of KPluginMetaData where we can
Summary: Instead of relying on the older KPluginInfo which is slower (parses de metadata twice) and comes from a much higher tier.
Test Plan: Running plasmashell with it
Reviewers: Plasma, mart
Reviewed By: Plasma, mart
Subscribers: kossebau, broulik, kde-frameworks-devel
Tags: Frameworks
Differential Revision: https://phabricator.kde.org/D23682