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/Bluetooth.qml

@@ -9,5 +9,7 @@ NIconButtonHot {
 
   icon: BluetoothService.enabled ? "bluetooth" : "bluetooth-off"
   tooltipText: I18n.tr("quickSettings.bluetooth.tooltip.action")
-  onClicked: PanelService.getPanel("bluetoothPanel")?.toggle(this)
+  onClicked: {
+    PanelService.getPanel("bluetoothPanel", screen)?.toggle(this)
+  }
 }