text: Title: Cleanup: kube-proxy internal naming
  Body: We have sort of a mish-mash of "service" and "servicePort" and similar.
  
  We should think about changing ALL of the places that actually relate to a service-port (a specific port of a service, not the whole service) and rename them to some new term that means "service port". E.g. "svcpt" or "spt" or "sport".
  
  See https://github.com/kubernetes/kubernetes/pull/106497/commits/8fffae321d66487f776922e0c313b33af7bf27e3 in pkg/proxy/iptables/proxier.go and friends.  e.g. `info.serviceNameString` -> `info.svcptNameString` ?