Resources are not cleaned up

Created by: chess-knight

#481 introduced separation of k8s clusters by namespace. Clusters are now in a separate namespace(with the same name as the cluster itself). It seems that this causes problems with all clean-up commands(delete_cluster.sh, make fullclean ...) and maybe other scripts(add_cluster-network.sh, enable-cilium-sg-kube.sh ...) where the hardcoded value default is used.

For e.g. after using make fullclean command, network and router k8s-clusterapi-cluster-testcluster-testcluster were not deleted from the OpenStack project.