Add support for preflight check configuration

[tmshort]

What this PR does / why we need it:

This adds configuration file support (preflightRules) for preflight checks. Each preflight check must add a SetConfig() method to accept configuration from the Preflight registry.

Which issue(s) this PR fixes:

Fixes #899

Does this PR introduce a user-facing change?

Add support for preflightRules configuration

Additional Notes for your reviewer:

Review Checklist:

• Follows the developer guidelines
• Relevant tests are added or updated
• Relevant docs in this repo added or updated
• Relevant carvel.dev docs added or updated in a separate PR and there's
  a link to that PR
• Code is at least as readable and maintainable as it was before this
  change

Additional documentation e.g., Proposal, usage docs, etc.:

Proposal carvel-dev/carvel#729

[praveenrewar]

Looks good to me apart from Bryce's comment.
Should we add/update the preflight permissions e2e tests with a config example? (I am okay with just the unit tests as well)

Would would also have to add the preflight option in the configuration docs.

[tmshort]

Looks good to me apart from Bryce's comment. Should we add/update the preflight permissions e2e tests with a config example? (I am okay with just the unit tests as well)

Would would also have to add the preflight option in the configuration docs.

I'll create a new PR for the docs.

The unit tests cover the code as written. IMHO, an e2e would be more appropriate once a preflight check adds configuration settings; otherwise, the e2e would effectively be a duplicate test.

[tmshort]

Documentation PR: carvel-dev/carvel#740

[praveenrewar]

LGTM! Thank you so much for the contribution ❤️