Draft: Feature/rapid cdn cache introspection
Attention
It shall be most possibly done on top of !1906 (closed) and it shall be proven that from outside world it's impossible to PURGE/DELETE the cache.
Reply: Access to the internal part of TrafficServer path is only possible from the special introspection frontend, and there are tests covering that verbs like DELETE arrive to the origin server and are processed by it, so the situation is covered.