Add a Palo Alto poller module

[menckend]

Want to be able to extract a mimic the routing configuration of a Palo Alto firewall for inclusion in the virtual-lab topology. Assuming that PA virtual-instances would be physically/financially impractical to instantiate in a virtual-lab, but hoping that their routing configuration/behavior is exposed via API to the point that it could be approximated on a lightweight container (cEOS seems like an obvious starting point.)