applet: Port to PC3, port to Qt Quick DragArea and Drop, plus some smaller changes
applet: Port to PC3, port to Qt Quick DragArea and Drop
This depends on changes to PC3 TabBar and TabButton: https://invent.kde.org/frameworks/plasma-framework/-/merge_requests/343
Port away from PC2 and away from KDeclarative DragArea and DropArea
applet: Use attached ToolTips
They're more RAM efficient and don't have visual glitches
applet: remove unused Header component
applet: Disable clipping on slider handle, enable layer
The clipping interferes with a focus ring effect I will be adding to PC3 slider and enabling layer prevents the groove from showing through the handle when opacity is reduced.
Edited by Noah Davis