Our integration tests need to be 'grouped' because each group often
needs a specific set of models it works with. We separated vision tests
due to this, and we have a separate set of tests which test "Responses"
API.
This PR makes this system a bit more official so it is very easy to
target these groups and apply all testing infrastructure towards all the
groups (for example, record-replay) uniformly.
There are three suites declared:
- base
- vision
- responses
Note that our CI currently runs the "base" and "vision" suites.
You can use the `--suite` option when running pytest (or any of the
testing scripts or workflows.) For example:
```
OLLAMA_URL=http://localhost:11434 \
pytest -s -v tests/integration/ --stack-config starter --suite vision
```
