Bar widgets: modular loading refactoring via BarWidgetRegistry+NWidgetLoader

- Hot reload is working again.
- Should also be more memory efficient on multi monitors.

Modules/Bar/Widgets/ActiveWindow.qml

@@ -9,13 +9,16 @@ import qs.Widgets
 
 Row {
   id: root
+
+  property ShellScreen screen
+  property real scaling: ScalingService.scale(screen)
+  property bool showingFullTitle: false
+  property int lastWindowIndex: -1
+
   anchors.verticalCenter: parent.verticalCenter
   spacing: Style.marginS * scaling
   visible: getTitle() !== ""
 
-  property bool showingFullTitle: false
-  property int lastWindowIndex: -1
-
   // Timer to hide full title after window switch
   Timer {
     id: fullTitleTimer