Verify and document migration from client-side to server-side apply with kpt live

[mortent]

We added support for server-side apply for kpt in https://github.com/kubernetes-sigs/cli-utils/pull/257, but I don't think we have fully explored the experience for updating from client-side to server-side apply. Even the k8s documentation isn't super specific on this: https://kubernetes.io/docs/reference/using-api/server-side-apply/#upgrading-from-client-side-apply-to-server-side-apply

[mortent]

Some open questions here:

• How does the migration work for situations where the field manager is something else than kubectl? Is there something special about the kubectl field manager during the process?
• What is the expectation on the use of the --force flag for migration?

[seans3]

A collaboration document with Spotify to work and document some of these issues: https://docs.google.com/document/d/14IWVExoFV8_TNQ0b8Uv2ROzh1o5bu2gijFzHWPIgCBw/edit?resourcekey=0-APC0pJG4_Qth2H9beP1z8Q#heading=h.iivv45yu16mq