Fix TrayMenu crash after display wake. Add checks if screen exists, else set scaling to 1.0

TrayMenu: Replace PopupPanel with NPanel (for better loading & to
prevent QS crash)
Overview, Background etc: add screen checks, if it doesnt exist set
scaling to 1.0

Modules/LockScreen/LockScreen.qml

@@ -93,7 +93,7 @@ Loader {
             id: lockBgImage
             anchors.fill: parent
             fillMode: Image.PreserveAspectCrop
-            source: WallpaperService.getWallpaper(screen.name)
+            source: screen ? WallpaperService.getWallpaper(screen.name) : ""
             cache: true
             smooth: true
             mipmap: false