feat: Add NVIDIA NeMo datastore (#1852)

# What does this PR do?
Implemetation of NeMO Datastore register, unregister API.

Open Issues: 
- provider_id gets set to `localfs` in client.datasets.register() as it
is specified in routing_tables.py: DatasetsRoutingTable
see: #1860

Currently I have passed `"provider_id":"nvidia"` in metadata and have
parsed that in `DatasetsRoutingTable`
(Not the best approach, but just a quick workaround to make it work for
now.)

## Test Plan
- Unit test cases: `pytest
tests/unit/providers/nvidia/test_datastore.py`
```bash
========================================================== test session starts ===========================================================
platform linux -- Python 3.10.0, pytest-8.3.5, pluggy-1.5.0
rootdir: /home/ubuntu/llama-stack
configfile: pyproject.toml
plugins: anyio-4.9.0, asyncio-0.26.0, nbval-0.11.0, metadata-3.1.1, html-4.1.1, cov-6.1.0
asyncio: mode=strict, asyncio_default_fixture_loop_scope=None, asyncio_default_test_loop_scope=function
collected 2 items                                                                                                                        

tests/unit/providers/nvidia/test_datastore.py ..                                                                                   [100%]

============================================================ warnings summary ============================================================

====================================================== 2 passed, 1 warning in 0.84s ======================================================
```

cc: @dglogo, @mattf, @yanxi0830

llama_stack/providers/remote/datasetio/nvidia/datasetio.py

@@ -0,0 +1,112 @@
+# Copyright (c) Meta Platforms, Inc. and affiliates.
+# All rights reserved.
+#
+# This source code is licensed under the terms described in the LICENSE file in
+# the root directory of this source tree.
+
+from typing import Any, Dict, List, Optional
+
+import aiohttp
+
+from llama_stack.apis.common.content_types import URL
+from llama_stack.apis.common.responses import PaginatedResponse
+from llama_stack.apis.common.type_system import ParamType
+from llama_stack.apis.datasets import Dataset
+
+from .config import NvidiaDatasetIOConfig
+
+
+class NvidiaDatasetIOAdapter:
+    """Nvidia NeMo DatasetIO API."""
+
+    def __init__(self, config: NvidiaDatasetIOConfig):
+        self.config = config
+        self.headers = {}
+
+    async def _make_request(
+        self,
+        method: str,
+        path: str,
+        headers: Optional[Dict[str, Any]] = None,
+        params: Optional[Dict[str, Any]] = None,
+        json: Optional[Dict[str, Any]] = None,
+        **kwargs,
+    ) -> Dict[str, Any]:
+        """Helper method to make HTTP requests to the Customizer API."""
+        url = f"{self.config.datasets_url}{path}"
+        request_headers = self.headers.copy()
+
+        if headers:
+            request_headers.update(headers)
+
+        async with aiohttp.ClientSession(headers=request_headers) as session:
+            async with session.request(method, url, params=params, json=json, **kwargs) as response:
+                if response.status != 200:
+                    error_data = await response.json()
+                    raise Exception(f"API request failed: {error_data}")
+                return await response.json()
+
+    async def register_dataset(
+        self,
+        dataset_def: Dataset,
+    ) -> Dataset:
+        """Register a new dataset.
+
+        Args:
+            dataset_def [Dataset]: The dataset definition.
+                dataset_id [str]: The ID of the dataset.
+                source [DataSource]: The source of the dataset.
+                metadata [Dict[str, Any]]: The metadata of the dataset.
+                    format [str]: The format of the dataset.
+                    description [str]: The description of the dataset.
+        Returns:
+            Dataset
+        """
+        ## add warnings for unsupported params
+        request_body = {
+            "name": dataset_def.identifier,
+            "namespace": self.config.dataset_namespace,
+            "files_url": dataset_def.source.uri,
+            "project": self.config.project_id,
+        }
+        if dataset_def.metadata:
+            request_body["format"] = dataset_def.metadata.get("format")
+            request_body["description"] = dataset_def.metadata.get("description")
+        await self._make_request(
+            "POST",
+            "/v1/datasets",
+            json=request_body,
+        )
+        return dataset_def
+
+    async def update_dataset(
+        self,
+        dataset_id: str,
+        dataset_schema: Dict[str, ParamType],
+        url: URL,
+        provider_dataset_id: Optional[str] = None,
+        provider_id: Optional[str] = None,
+        metadata: Optional[Dict[str, Any]] = None,
+    ) -> None:
+        raise NotImplementedError("Not implemented")
+
+    async def unregister_dataset(
+        self,
+        dataset_id: str,
+    ) -> None:
+        await self._make_request(
+            "DELETE",
+            f"/v1/datasets/{self.config.dataset_namespace}/{dataset_id}",
+            headers={"Accept": "application/json", "Content-Type": "application/json"},
+        )
+
+    async def iterrows(
+        self,
+        dataset_id: str,
+        start_index: Optional[int] = None,
+        limit: Optional[int] = None,
+    ) -> PaginatedResponse:
+        raise NotImplementedError("Not implemented")
+
+    async def append_rows(self, dataset_id: str, rows: List[Dict[str, Any]]) -> None:
+        raise NotImplementedError("Not implemented")