Automatic merge from submit-queue (batch tested with PRs 66235, 66908, 66907). 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>.
switch kubectl portfoward to external types
switch the guts of portforward to external types.
@kubernetes/sig-cli-maintainers
```release-note
NONE
```