node-proxy: send oob management requests to the MgrListener()

node-proxy: send oob management requests to the MgrListener()

Note that this won't be a true out of band management.
In the case where the host hangs, this won't work. The oob
management should be reached directly but most of the time
the oob network is isolated. The idea is to send queries to the
the tcp server exposed by the cephadm agent (MgrListener) so it
can send itself queries to the redfish API using the IP address
exposed on the OS.

Signed-off-by: Guillaume Abrioux <gabrioux@ibm.com>