tried with minimal QML files, a more comprehensive gallery may be needed.
pending considerations:
* some of the classes, like Drawer, the dialogs and ApplicationWindow *don't* make sense in plasmoids
* it will probably still need to be installed also as a qqc2 style, as this should be used in Plasma mobile
* probably only some of the controls should be installed as a separate import, the whole set as a style strictly for Plasma Mobile use. the same qml files would be used, so no maintainance overhead