Add support for VRF features

[displague]

What problem are you facing?

VRF features are being added to the IP, Gateway, and Virtual Circuit resources in the Equinix Metal API.
https://deploy.equinix.com/developers/docs/metal/interconnections/vrf/

There is no way to access these features in the Metal CLI today.

How could the Equinix Metal CLI help solve this problem?

The existing metal gateway and metal ip action groups should learn new actions and add relevant fields based on VRF capabilities.

Packngo support for VRF was initially added here: equinixmetal-archive/packngo#325

Metal Go support is present (and more current than packngo's support): https://github.com/search?q=repo%3Aequinix-labs%2Fmetal-go%20vrf&type=code

Examples of how this could be implemented are in @goldenprifti's Equinix Metal VRF CLI gist here: https://gist.github.com/goldenprifti/850fa74cb08c23b4e3ebac2b01746bab

These features should also be added to a metal interconnection action group (which does not exist today #307).

[displague]

Here's an example of some of the commands that will be needed to support the new /vrfs API endpoint (https://github.com/equinix-labs/metal-go/blob/main/docs/VRFsApi.md):

metal vrf create --project-id {project}
metal vrf delete --id {id}
metal vrf list --project-id {project}
metal vrf get --id {id} # same as list, but id is specified. similar to other get/list actions
metal vrf update --id {id}

metal routes create --vrf-id {vrf}
metal routes update --id {id}
metal routes get --id {id}
metal routes delete --id {id}

In addition to the new arguments for ips and gateways, for full VRF coverage, we'll also need new commands around metal interconnection and metal virtual-circuit.