Implement negative caching for HS descriptor
A negative cache object will have to expire at some point to be removed from cache else a memory DoS would be trivial here.
I guess for that we will need to have an expiry time of the cache object and how many bad fetch before caching the desc.
We have to be careful also on the rate we accept negative caching to avoid memory exhaustion if let say we get 10k bad desc request in 10 seconds.