Open up Victoria Metrics query engine to the public

@mattrighetti has been wondering if VictoriaMetrics (VM for short) can be opened to the public so the API doesn't have to proxy requests to the DB but can just pass a 302 code and clients can query VM directly.

I personally have a concern that services will abuse the VM search engine and crash our service, and I am wondering what we could do to prevent this. I am specifically wondering if is there some token system where only authorized clients could query VM.