Add Terra Testing to demo configuration

[jamesptruitt]

94

PR Checklist

---

• [X] I have updated the documentation accordingly.
• [X] I have added tests to cover my changes.
• [X] All new and existing tests passed.
• [X] My code follows the code style of this project.
• [X] I ran lint checks locally prior to submission.
• [X] Have you checked to ensure there aren't other open Pull Requests for the same update/change?

Description

Adding Terra Testing to demo configuration. This testing is for Levels 0,1,2-Networking, 2-SharedServices, 3-AML and 3-AKS. Level 3-AppService not implemented.

Does this introduce a breaking change

• [ ] YES
• [X] NO

Testing

Follow instructions in configuration\demo\README.md

[arnaudlh]

thanks for the PR @jamesptruitt and sorry it took some time to merge ;)