text: Title: Replace kubernetes/pkg/util/net/sets with code in k8s.io/utils/net/
  Body: At some point, the code in https://github.com/kubernetes/kubernetes/tree/master/pkg/util/net/ (net.go and ipnet.go) was moved to https://github.com/kubernetes/utils/tree/master/net
  
  However we have not started using the code in the kubernetes/utils library. We should switch over to the vendored library and delete the duplicate code in the main repo.