Lot of things

Refactored Role enum to be the same as Keycloak roles
Managed CORS errors in backend
Edited Keycloak config to avoid CORS error
Edited frontend API to avoid CORS errors
Changed Activite creation management
Added debug print in Login (should be removed);

back_end/package-lock.json

@@ -0,0 +1,6 @@
+{
+  "name": "back_end",
+  "lockfileVersion": 3,
+  "requires": true,
+  "packages": {}
+}