change schema -> dataset_schema for register_dataset api (#443)

# What does this PR do?

- API updates: change schema to dataset_schema for register_dataset for
resolving pydantic naming conflict
- Note: this OpenAPI update will be synced with
llama-stack-client-python SDK.

cc @dineshyv 

## Test Plan

```
pytest -v -s -m meta_reference_eval_together_inference_huggingface_datasetio eval/test_eval.py
```

## Sources

Please link relevant resources if necessary.


## Before submitting

- [ ] This PR fixes a typo or improves the docs (you can dismiss the
other checks if that's the case).
- [ ] Ran pre-commit to handle lint / formatting issues.
- [ ] Read the [contributor
guideline](https://github.com/meta-llama/llama-stack/blob/main/CONTRIBUTING.md),
      Pull Request section?
- [ ] Updated relevant documentation.
- [ ] Wrote necessary unit or integration tests.

docs/resources/llama-stack-spec.html

@@ -21,7 +21,7 @@
     "info": {
         "title": "[DRAFT] Llama Stack Specification",
         "version": "0.0.1",
-        "description": "This is the specification of the llama stack that provides\n                a set of endpoints and their corresponding interfaces that are tailored to\n                best leverage Llama Models. The specification is still in draft and subject to change.\n                Generated at 2024-11-12 15:47:15.607543"
+        "description": "This is the specification of the llama stack that provides\n                a set of endpoints and their corresponding interfaces that are tailored to\n                best leverage Llama Models. The specification is still in draft and subject to change.\n                Generated at 2024-11-13 11:02:50.081698"
     },
     "servers": [
         {
@@ -5170,7 +5170,7 @@
                         "const": "dataset",
                         "default": "dataset"
                     },
-                    "schema": {
+                    "dataset_schema": {
                         "type": "object",
                         "additionalProperties": {
                             "oneOf": [
@@ -5352,7 +5352,7 @@
                     "provider_resource_id",
                     "provider_id",
                     "type",
-                    "schema",
+                    "dataset_schema",
                     "url",
                     "metadata"
                 ]
@@ -6678,7 +6678,7 @@
                     "dataset_id": {
                         "type": "string"
                     },
-                    "schema": {
+                    "dataset_schema": {
                         "type": "object",
                         "additionalProperties": {
                             "oneOf": [
@@ -6863,7 +6863,7 @@
                 "additionalProperties": false,
                 "required": [
                     "dataset_id",
-                    "schema",
+                    "dataset_schema",
                     "url"
                 ]
             },
@@ -7837,58 +7837,58 @@
     ],
     "tags": [
         {
-            "name": "Safety"
-        },
-        {
-            "name": "EvalTasks"
-        },
-        {
-            "name": "Shields"
-        },
-        {
-            "name": "Telemetry"
-        },
-        {
-            "name": "Memory"
-        },
-        {
-            "name": "Scoring"
-        },
-        {
-            "name": "ScoringFunctions"
-        },
-        {
-            "name": "SyntheticDataGeneration"
+            "name": "Inspect"
         },
         {
             "name": "Models"
         },
         {
-            "name": "Agents"
+            "name": "Eval"
         },
         {
-            "name": "MemoryBanks"
+            "name": "EvalTasks"
         },
         {
-            "name": "DatasetIO"
+            "name": "Scoring"
         },
         {
             "name": "Inference"
         },
         {
-            "name": "Datasets"
+            "name": "Memory"
+        },
+        {
+            "name": "Safety"
         },
         {
             "name": "PostTraining"
         },
+        {
+            "name": "ScoringFunctions"
+        },
+        {
+            "name": "Telemetry"
+        },
+        {
+            "name": "Shields"
+        },
         {
             "name": "BatchInference"
         },
         {
-            "name": "Eval"
+            "name": "MemoryBanks"
         },
         {
-            "name": "Inspect"
+            "name": "Datasets"
+        },
+        {
+            "name": "SyntheticDataGeneration"
+        },
+        {
+            "name": "DatasetIO"
+        },
+        {
+            "name": "Agents"
         },
         {
             "name": "BuiltinTool",