This change moves the services LB creation from kubernetes nodepool
to kubernetes cluster nexus, alongside the apiserver lb creation.
We still don't know how to support multiple nodepools and their
relationship to service LBs, but it's simpler to assume that we will
support a single service LB for the whole cluster.
This change also starts using the FK for the service LB reference,
instead of the name based query.
76d7bff0d4