ifconfig: Add SR-IOV VF status output

[kbowling]

Summary

ifconfig: Add SR-IOV VF status output

Add NIC-specific VF status to the existing ifconfig -v output. Request
and display the data through ifconfig’s native route Netlink interface.

Group optional identity, initialization, resources, VLAN policy,
administrator policy, protocol, and runtime-blocking fields.  Omitted
fields remain distinct from false or zero.  Refer users to iovctl -L
for device-neutral PCI attachment and passthrough state.

This is a Netlink-native evolution of the original interface by Eric
Joyner.

Relnotes:       yes

Co-authored-by: Eric Joyner <[e-mail]>