N°6934 - Symfony 6.4 - upgrade Symfony bundles to 6.4 (#580)

* Update Symfony lib to version ~6.4.0
* Update code missing return type
* Add an iTop general configuration entry to store application secret (Symfony mandatory parameter)
* Use dependency injection in ExceptionListener & UserProvider classes

lib/symfony/web-profiler-bundle/Resources/views/Icon/settings-theme-system.svg

@@ -0,0 +1,5 @@
+<svg xmlns="http://www.w3.org/2000/svg" data-icon-name="icon-tabler-device-laptop" width="24" height="24" viewBox="0 0 24 24" stroke-width="1.5" stroke="currentColor" fill="none" stroke-linecap="round" stroke-linejoin="round">
+    <path stroke="none" d="M0 0h24v24H0z" fill="none"/>
+    <line x1="3" y1="19" x2="21" y2="19" />
+    <rect x="5" y="6" width="14" height="10" rx="1" />
+</svg>