Make it possible to run a test group in Drush

Attaching example terminal output for ddev drush agents:test-agents --group_id=1 --uid=1

Attaching example terminal output when overriding the LLM evaluation model.
ddev drush agetes --group_id=1 --uid=1 --eval_provider=openai --eval_model=o3

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Added a 3rd test to the group that asserts basic_page content type is not promoted. This will of course fail.

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Bonus, added approximate execution time…

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And what it looks like in detailed mode…

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