Adds labels used by ViNO & SIP to schedule subcluster VMs appropriately,
for rack and undercloud server name.
This also trues up the label definitions in the SIP CRs to match.
This change can be merged independently of the related change to airshipctl:
https://review.opendev.org/c/airship/airshipctl/+/797130
Change-Id: I6cf2bc653589d142736990cdfadf82641a6ca4d1