Add verify_ports to agent verification

Listens for LLDP info on all interfaces, then attempts to match that to
the ports Ironic has, raising Verification errors if they don't match up.

Relies on https://review.openstack.org/#/c/92627/ for LLDP tools in the Agent.
Instead of all this silliness, why not just look directly at `hardware/interfaces/{0,1}/...`? This HW manager is onmetal-specific, don't see any reason to generalize right now.