Support atlantis test subcommand

[nitrocode]

Community Note

• Please vote on this issue by adding a 👍 reaction to the original issue to help the community and maintainers prioritize this request. Searching for pre-existing feature requests helps us consolidate datapoints for identical requirements into a single place, thank you!
• Please do not leave "+1" or other comments that do not add relevant new information or questions, they generate extra noise for issue followers and do not help prioritize the request.
• If you are interested in working on this issue or have submitted a pull request, please leave a comment.

---

• I'd be willing to implement this feature (contributing guide)

Describe the user story

Support terraform test

Describe the solution you'd like

See above

Describe the drawbacks of your solution

None

Describe alternatives you've considered

N/A

references

• Support remaining atlantis terraform commands #2776