Create k8s-specific E2E testing workflows #1026

Currently we have e2e testing for the cluster-based image. As we move away from the cluster image and allow installing onto existing Kubernetes cluster, we need to be able to run our tests within a CI environment that exercises the same set of tests we have today in the e2e-test workflow.

Criteria:

1. Standup a k3s cluster and install the OpenShell helm chart (with container images loaded or accessible)
2. Expose the Gateway outside of the cluster accessible to the e2e test runner
3. Run the e2e-tests
4. Capture test failures and artifacts (logs, etc).