Foreman » Smart Proxy

Fixes #8905 - bind_port config option

Fixes #7849 - re-factor trusted_hosts handling

On HTTPS we will get the FQDN from the client certificate and check against the
list.

While on HTTP we will perform both reverse DNS and forward DNS lookup to verify
the client may talk to us.

Additionally the forward_verify of DNS can be disabled.

Fixes #4866: Breaking up monolithic smart-proxy into modules