Dependency on old version of kapp-controller, ytt should be removed

When using kapp as library it adds:
- kapp-controller's old version as indirect dependency because of this line https://github.com/carvel-dev/kapp/blob/develop/go.mod#L19
- ytt old version as indirect dependency because of this line https://github.com/carvel-dev/kapp/blob/develop/go.mod#L13

**What did you expect:**
kapp-controller depends on kapp, and so kapp should not depend on kapp-controller.
Dependency on ytt and other libs should be upgraded so that they ingest carvel.dev instead

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