Support tests of private ArcGIS Enterprise endpoints

[pbobov]

In the current design arcgis-enterprise-base-aws test workflow calls base ArcGIS Enterprise service endpoints from GitHub Actions runner container. This will not work if

• Access to the endpoints is blocked by a firewall, or
• The endpoint is not accessible from the internet at all.

The test should run in a VM or container within the VPC subnets used by the application load balancer. In particular, the tests could use AWS ECS or AWS Lambda (serverless) services.

[pbobov]

Solved for K8s by running tests in the EKS cluster.

So far there is no good solution for Windows and Linux. Windows and Linux tests were redesigned to run in Docker containers. But running the containers inside the site's VPC requires a container orchestration service such as ECS. This would complicate the system architecture.