Put all systemwide add-ons in Plasma Addons category
Summary:
BUG: 390594
FIXED-IN: Plasma 5.12.2
Test Plan:
Application Addons category now only has actual app-specific addons:
Plasma Addons category is now nice and full of actual Plasma (or other system-level) add-ons:
Reviewers: Discover Software Store, apol
Subscribers: plasma-devel
Tags: Plasma
Differential Revision: https://phabricator.kde.org/D10611