Update OpenShift router to recognize a new annotation key "haproxy.router.openshift.io/ip_allowlist" in addition to the old "haproxy.router.openshift.io/ip_whitelist" annotation key. Continue to allow the old annotation key for now, but use the new one if it is present.

In a future release, we may remove the old annotation key, after allowing ample time for route owners to migrate to the new one. (We may also consider replace the annotation with a formal API field.)