Bring back the Acceptance Test Harness

[dduportal]

As underlined in #2235 Serverpsec tests are deprecated since Q1 2021 (the vagrant plugin is not maintained anymore and is not working with Vagrant 2.x).

We should bring back a test harness as part of the vagrant acceptance testing:

• either find a solution to run ServerSpec v2 inside the vagrant "instance", after the puppet provision, and returns an exit code based on its status + test reports.
  • Pros: we might be able to reuse the existing serverspec logic + rpsec is the same language as for unit tests (but with different assertion resources though)
• OrsSwitch to Goss as it can also be used for Docker with the dgoss wrapper and provides automatic adding tests