New windowing system

Large commit that totally refactor of the way we handle the bar and
panels.

Testing should focus on Panels, Bar, Keyboard Focus, IPC calls.

Changes brief:
- One NFullScreenWindow per screen which handle it's bar and dedicated
panels.
- Added shadows
- Reintroduced dimming
- New panels animations
- Proper Z ordering
- Panels on overlay laywer is not reimplemented, if we do it then the
bar will be on the Overlay too
- Panel dragging was not reimplemented, to be discussed before
reimplementing
- Still a WIP, need to work more on shadows and polishing + debugging.

Modules/ControlCenter/Widgets/PowerProfile.qml

@@ -14,7 +14,7 @@ NIconButtonHot {
   enabled: hasPP
   icon: PowerProfileService.getIcon()
   hot: !PowerProfileService.isDefault()
-  tooltipText: hasPP ? I18n.tr("quickSettings.powerProfile.tooltip.action") : I18n.tr("quickSettings.powerProfile.tooltip.disabled")
+  tooltipText: I18n.tr("quickSettings.powerProfile.tooltip.action")
   onClicked: {
     PowerProfileService.cycleProfile()
   }