feat(tests): introduce a test "suite" concept to encompass dirs, options (#3339)

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
```

.github/actions/setup-test-environment/action.yml

@@ -12,10 +12,10 @@ inputs:
     description: 'Provider to setup (ollama or vllm)'
     required: true
     default: 'ollama'
-  run-vision-tests:
-    description: 'Whether to setup provider for vision tests'
+  test-suite:
+    description: 'Test suite to use: base, responses, vision, etc.'
     required: false
-    default: 'false'
+    default: ''
   inference-mode:
     description: 'Inference mode (record or replay)'
     required: true
@@ -33,7 +33,7 @@ runs:
       if: ${{ inputs.provider == 'ollama' && inputs.inference-mode == 'record' }}
       uses: ./.github/actions/setup-ollama
       with:
-        run-vision-tests: ${{ inputs.run-vision-tests }}
+        test-suite: ${{ inputs.test-suite }}
 
     - name: Setup vllm
       if: ${{ inputs.provider == 'vllm' && inputs.inference-mode == 'record' }}