N°2435.1 Portal: Split portal composer.json in 2

- Autoloader for portal files in the itop-portal-base module
- Dependencies moved to root composer.json
- Add autoloader for /core and /application content

lib/symfony/framework-bundle/Tests/DependencyInjection/Fixtures/php/session.php

@@ -0,0 +1,7 @@
+<?php
+
+$container->loadFromExtension('framework', [
+    'session' => [
+        'handler_id' => null,
+    ],
+]);