Update Rego "Prerequisites" for policy API

[adhilto]

💡 Summary

Update the "Prerequisites" field for each Rego test to indicate if it relies on the policy or reports API.

Motivation and context

Seehttps://github.com//pull/163 for a description of the error handling ScubaGoggles performs, relevant to this issue. Specifically:

1. The Provider tracks which API calls/functions succeed/fail
2. The Rego tests are modified to list which API calls/functions they depend on.
3. The Reporter checks to see if the prerequisites were met before displaying the result.

Currently, not all Rego "tests" have a Prerequisites field. As noted in a comment in the reporter, "If Prerequisites is not defined, assume the test just depends on the reports API." With the addition of the policy API, this is no longer a safe assumption.

Implementation notes

Two different options here.

1. Ensure that each Rego "test" has a Prerequisites field, noting its dependence on the policy, reports, or other API (e.g., groups).
2. Add the reports API dependency to the Rego tests that rely on that, then modify the Reporter to assume that if no prerequisites are defined, that the test just depends on the policy API.

The second option would result in less Rego changes short-term.

Acceptance criteria

• The applicable Rego tests have been updated
• The provider tracks whether or not the policy API call succeeds or fails
• The Reporter has been updated as needed