Panel settings redesign: plasmashell part
In the new design for the panel settings, the main window is now a PopupPlasmawindow with the main controls, and an ancillary window which is a "panel" for the ruler view visible only when the panel sizing is custom.
The contents and the UI for those will come from the shell package in plasma-desktop.
Supports plasma-desktop!1723 (merged).
Edited by Nate Graham