BFD early networking support.

[rcgoodfellow]

In

• 4852

the only way to enable BFD is after a rack install. For some network configurations, it may be necessary to set up BFD during rack installation.

[rcgoodfellow]

Deprioritizing as

• oxidecomputer/maghemite#174

has landed and should provide a viable early-networking path for BFD-based networks. This still needs to happen but not for release 7.

[rcgoodfellow]

Partially addressed in

• 5313

And BFD is present in the RSS/rack-setup data structures

• https://github.com/oxidecomputer/omicron/blob/4dda5cbba6c7bd4d47df79cf0001a7873abd21b8/common/src/api/internal/shared.rs#L160-L175

However, it's missing from wicket

• https://github.com/oxidecomputer/omicron/blob/4dda5cbba6c7bd4d47df79cf0001a7873abd21b8/wicket-common/src/rack_setup.rs#L101-L109

[rcgoodfellow]

Moving this to 10, as not having BFD in wicket is not a blocker for R9.