create new building target 'GenerateTests'

[changlong-liu]

Description

This is the step 1 for issue #3086

Checklist

To ensure a quick review and merge, please ensure:

• The PR has a understandable title and description explaining the why and what.
• The PR is opened in draft if not ready for review yet.
  • If opened in draft, please allocate sufficient time (24 hours) after moving out of draft for review
• The branch is recent enough to not have merge conflicts upon creation.

Ready to Land?

• Build is completely green
  • Submissions with test failures require tracking issue and approval of a CODEOWNER
• At least one +1 review by a CODEOWNER
• All -1 reviews are confirmed resolved by the reviewer
  • Override/Marking reviews stale must be discussed with CODEOWNERS first