fix(terraform): Handled nested unrendered vars

[mikeurbanski1]

By submitting this pull request, I confirm that my contribution is made under the terms of the Apache 2.0 license.

Description

Adds logic to handle unrendered variables for custom policies that use nested attributes, like checking for a specific tag.

Previously, tags.component equals ... for tags = local.unrendered_var would fail because the value of that attribute is None, and this doesn't get picked up as an unrendered var. The fix is to check each attribute part (first tags, then tags.component) to see if it maps to an unrendered var.

Additionally, , a policy like tags.component exists would fail for tags = local.unrendered_var, because of the is_value_attribute_check condition. This PR modifies that behavior to only care about is_value_attribute_check when we are evaluating the literal attribute in the policy (tags.component, not just tags).

This PR also adds some explicit tests for simple and nested unrendered variables for conditions with and without value, since it seemed like those were missing. (They are just reflected in changed results of other tests for other things).

Checklist:

• My code follows the style guidelines of this project
• I have performed a self-review of my own code
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• I have added tests that prove my feature, policy, or fix is effective and works
• New and existing tests pass locally with my changes
• Any dependent changes have been merged and published in downstream modules

[rotemavni]

Nice!

[gruebel]

noice 🍺