feat(dataset api): (1.6/n) fix all iterrows callsites (#1660)

# What does this PR do?
- as title

[//]: # (If resolving an issue, uncomment and update the line below)
[//]: # (Closes #[issue-number])

## Test Plan
CI

```
pytest -v -s --nbval-lax ./docs/notebooks/Llama_Stack_Benchmark_Evals.ipynb
```
<img width="587" alt="image"
src="https://github.com/user-attachments/assets/4a25f493-501e-43f4-9836-d9802223a93a"
/>


[//]: # (## Documentation)

llama_stack/distribution/ui/page/evaluations/native_eval.py

@@ -166,11 +166,10 @@ def run_evaluation_3():
     eval_candidate = st.session_state["eval_candidate"]
 
     dataset_id = benchmarks[selected_benchmark].dataset_id
-    rows = llama_stack_api.client.datasetio.iterrows(
+    rows = llama_stack_api.client.datasets.iterrows(
         dataset_id=dataset_id,
-        rows_in_page=-1,
     )
-    total_rows = len(rows.rows)
+    total_rows = len(rows.data)
     # Add number of examples control
     num_rows = st.number_input(
         "Number of Examples to Evaluate",
@@ -195,7 +194,7 @@ def run_evaluation_3():
     if st.button("Run Evaluation"):
         progress_text = "Running evaluation..."
         progress_bar = st.progress(0, text=progress_text)
-        rows = rows.rows
+        rows = rows.data
         if num_rows < total_rows:
             rows = rows[:num_rows]