Use NULL for nick/blurb in GObject params

As they are only used by gstreamer for gst-inspect & other tools.
Projects like Mutter/gtk have completely dropped them as well, so follow
their path

Part-of: <https://gitlab.gnome.org/GNOME/gnome-shell/-/merge_requests/3505>

js/ui/overviewControls.js

@@ -259,7 +259,7 @@ class ControlsManagerLayout extends Clutter.LayoutManager {
 export const OverviewAdjustment = GObject.registerClass({
     Properties: {
         'gesture-in-progress': GObject.ParamSpec.boolean(
-            'gesture-in-progress', 'Gesture in progress', 'Gesture in progress',
+            'gesture-in-progress', null, null,
             GObject.ParamFlags.READWRITE,
             false),
     },