Automatic merge from submit-queue (batch tested with PRs 63871, 63927, 63966, 63957, 63844). 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>.

 start splitting polymorphic functions out of the factory

the polymorphic behavior in `kubectl` has been gathered in the factory, but with the new kubeconfigflags and interfaces, it can actually be re-written as a set of helper calls.

These functions are special.  They are indications of areas of flexibility that we eventually need to build generically.  In addition, unit tests make heavy use of injection. For these reasons we aren't inlining them.  Instead we'll extra to a polymorphic package and have them as assignable functions for mocking.

Individual commands should support injection for cleaner mocking and we'll be able to use the package to hunt internal dependencies.

@kubernetes/sig-cli-maintainers 
@soltysh @juanvallejo 

```release-note
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