status/network: Add activate() in NMSection

As the sections are about to turn into quick toggles, they need
to be able to perform an action on click.

Add an activate() method for that purpose, which either disconnects
all active items, or connects the primary item.

Part-of: <https://gitlab.gnome.org/GNOME/gnome-shell/-/merge_requests/2408>

js/ui/status/network.js

@@ -1343,6 +1343,15 @@ const NMSection = GObject.registerClass({
         this.menu.actor.visible = visible;
     }
 
+    activate() {
+        const activeItems = [...this._getActiveItems()];
+
+        if (activeItems.length > 0)
+            activeItems.forEach(i => i.activate());
+        else
+            this._itemBinding.source?.activate();
+    }
+
     _loadInitialItems() {
         throw new GObject.NotImplementedError();
     }