applets: Opt into abstract item drags
When dragging an app out of Kickoff, Kicker, Dashboard, or Task Manager, the app being backed by a desktop file is an implementation detail that produces a worse UX in the drop menu. Fix this by opting into the "Abstract item" drag behavior from KIO (frameworks/kio!1726).
BUG: 446031 FIXED-IN: 6.3.0