Consider the evolution of apis and the effects it has on usability of packaging artifacts

As we inevitably evolve the current APIs, we should consider what impact this will have on out of date artifacts and their compatibility with various versions of kapp-controller.

Some example questions to get started:
1. When new fields are added to packages, will package repos containing the newer packages still work as intended on older version of kapp-controller?
2. Vice versa of above: will older repos work on newer versions of kapp-controller
3. What would happen if we renamed a CR?
4. What would happen if we increased an apiVersion?
5. What are the repercussions of supporting multiple apiVersions (such as alpha and beta)?

Acceptance criteria: Create a brainstorming document and get feedback from the team.