WIP: impl forbidden page

lib/views/widget/forbidden_content.html

@@ -1,3 +1,8 @@
+{% block html_head_loading_legacy %}
+  <script src="{{ webpack_asset('js/legacy-form.js') }}" defer></script>  {# load legacy-form for using bootstrap-select(.selectpicker) #}
+  {% parent %}
+{% endblock %}
+
 <div class="row not-found-message-row m-b-20">
   <div class="col-md-12">
     <h2 class="text-muted">