feat(ironic): Add update_baremetal_port ironic inspection hook

[stevekeay]

Understack operation requires that every baremetal node has baremetal ports for each NIC we want to use.

Upstream ironic includes inspection hooks which can create baremetal ports and set local_link_info based on LLDP information, but UnderStack requires that Baremetal ports have specific attributes populated:

1. Exactly ONE of the ports on a node have set the pxe flag set. We put this port into the provisioning/cleaning network to boot the IPA image. (Putting multiple ports into the provisioning/cleaning VLAN causes DHCP and ARP issues, so we nominate a single port to boot from. This should be the same port that the actual server will attempt to use to make PXE requests).
2. local_link field must be populated with upstream connected switch HOSTNAME and INTERFACE name. We use these to drive switch automation.
3. physical_network field must be populated with the appropriate VLAN Group name. We use this to drive VLAN number assignment and switch configuration.

In addition, the baremetal node should have traits indicating the networks (VLAN Groups) to which it is connected, for example if it has NICs connected to the STORAGE switch then we would add the CUSTOM_STORAGE_SWITCH trait.

Switch uplink connections for the node are identified during node inspection using LLDP. The "agent" inspector does this today, and we are enhancing the out-of-band inspection to provide the same data (where the hardware permits).

This inspection hook is understack-specific in that it assumes our switch hostnames will follow a certain naming convention, however the details of that convention are supplied as configuration.

We previously performed these activities as part of the "enrol" process, but performing these activities inside Ironic gives operators more visibility and allows them to drive remediation or updates via the openstack API. For example, if a physical node had cabling issues during enrol, these can be resolved and the node can be "inspected" to straighten out the baremetal ports without needing to trigger an external workflow or process.

Once this PR is done, we can remove those steps from the enrol process - see #1416

PREREQUISITES

Today when a node undergoes cleaning, provisioning or agent inspection, all but one of its ports are shut down. This defeats LLDP and prevents the inspection from seeing the link on the other ports. We need to change our network design/template so that during inspection all ports are UP (and talk LLDP) but don't have any other traffic. This includes ports already documented in ironic (being re-inspected) as well as ports that are currently unknown (ports being discovered and created in ironic for the first time).

NOTE that when these baremetal port updates occur, ironic emits events which should trigger a workflow to make corresponding changes in nautobot)