Automatic merge from submit-queue. If you want to cherry-pick this change to another branch, please follow the instructions <a href="https://github.com/kubernetes/community/blob/master/contributors/devel/cherry-picks.md">here</a>. fed: Move cluster generator & constants from kubectl to kubefed pkg This will ensure the history of the federation-only files can be cheaply retained during the branch filtering that will occur for #52992. cc: @kubernetes/sig-multicluster-pr-reviews /sig multicluster /area federation /assign irfanurrehman shashidharatd /release-note-none