[WebProfilerBundle] Fix form panel expanders

Author: MatTheCat

src/Symfony/Bundle/WebProfilerBundle/Resources/views/Collector/form.html.twig

@@ -411,6 +411,7 @@
         };
 
     tabTarget.initTabs(document.querySelectorAll('.tree .tree-inner'));
+    toggler.initButtons(document.querySelectorAll('.toggle-button'));
     </script>
 {% endblock %}