EZP-21118: Implemented CORS support for the REST API

Uses NelmioCorsBundle.
Fix EZP-22101: Tweaked DefaultRouter param loading

The configResolver was used too early in a condition,
and was instanciating the legacy DB too early.
EZP-21118: Fixed EventListener test
Merge branch 'master' into story/EZP-21118-HTTP_CORS

Conflicts:
	composer.json
Merge branch 'story/EZP-21118-HTTP_CORS'