properly install whole plasmacomponent3

Summary:
right now just a subsection of controls are installed under plasmacomponent3
which makes for random missing stuff, especially any new component added.
it was done to avoid to have things like "applicationwindow" which don't make sense
in plasma, tough those are already available anyways as plain qqc2
install the whole folder avoiding many potential headaches

Test Plan: ieverything still works, all the components are available

Reviewers: Plasma, apol

Reviewed By: apol

Subscribers: kde-frameworks-devel

Tags: Frameworks

Differential Revision: https://phabricator.kde.org/D24072