A new service type is introduced which is used by the KCM to find
all available window switcher layouts. This makes it finally possible
to have 3rd party window switchers.
Also the tabbox finds the packaged QML file through the service
definitions.
Desktop switcher is not yet in packaged version (UI to configure
is missing).
REVIEW: 103951
By default clip is enabled. This means that if the thumbnail would
overlap the "parent" window, it does not get rendered at all. If set
to false it will always be rendered. This is required for window strip
where the complete screen width is used, so overlap does not matter.
This is useful in combination of non-modal TabBox through DBus and
window-strip layout. With DBus the non-modal TabBox can be started
and selecting any item on the strip will end TabBox again.
