N°8771 - Add Symfony form component to iTop core (#760)

- Add Symfony Form Component
- Add Symfony CSRF security component
- Add iTop default form template
- Add Twig debug extension to Twig Environment
- Add iTop abstract controller facility to get form builder
- Add Twig filter to make trans an alias of dict_s filter

templates/application/forms/itop_base_layout.html.twig

@@ -0,0 +1,4 @@
+{% use "form_div_layout.html.twig" %}
+
+{# Widgets #}
+