feat: put the access codes behind a feature flag

composer.json

@@ -10,6 +10,7 @@
         "doctrine/doctrine-bundle": "^3.3",
         "doctrine/doctrine-migrations-bundle": "^4.0",
         "doctrine/orm": "^3.7",
+        "flagception/flagception-bundle": "^6.0",
         "knplabs/knp-paginator-bundle": "^6.10",
         "league/oauth2-client": "^2.9",
         "phpdocumentor/reflection-docblock": "^6.0",