Evaluate & Reconcile OPA (Open Policy Agent) Gatekeeper with new pipeline infra

Currently we have no testing. Enhanced testing should at a minimum:

Bash:

• ??? <-- results of evaluation, what can we test?

When the testing infra is fully in place and decided these tests should be run by the new infra (helm tests / helm chart library).

See: https://repo1.dso.mil/platform-one/big-bang/bigbang/-/issues/297 & https://repo1.dso.mil/platform-one/big-bang/bigbang/-/issues/298