Expose metrics using https

[milap-form3]

Is your feature request related to a problem? Please describe.
The /metrics endpoint exposed is only serving via http which is not within compliance and we require the traffic to be encrypted using https.

Describe the solution you'd like
Be able to enable https from configuration. We could add configuration options like:

namespace "cluster_ingress_proxy" {
  listen {
    port = 4040
    protocol=https
    ssl-server-cert="/path/to/tls.crt"
    ssl-server-key="/path/to/tls.key"
  }
}

Describe alternatives you've considered
There is not much of a alternative unless we add something proxying the https connection

Additional context