chore: OpenAI compatibility for Milvus (#2470)

# What does this PR do?
Closes https://github.com/meta-llama/llama-stack/issues/2461



## Test Plan
Tested with the `ollama` distriubtion template and updated the vector_io
provider to:
```yaml
vector_io:
- provider_id: milvus
  provider_type: inline::milvus
  config:
    db_path: ${env.SQLITE_STORE_DIR:=~/.llama/distributions/ollama}/milvus_store.db
    kvstore:
      type: sqlite
      db_name: milvus_registry.db
```

Ran the stack
```bash
llama stack run ./llama_stack/templates/ollama/run.yaml --image-type venv --env OLLAMA_URL="http://0.0.0.0:11434"
```

Ran the tests:
```
pytest -sv --stack-config=http://localhost:8321 tests/integration/vector_io/test_openai_vector_stores.py  --embedding-model all-MiniLM-L6-v2
```
Output passed.

Signed-off-by: Francisco Javier Arceo <farceo@redhat.com>

llama_stack/providers/inline/vector_io/milvus/__init__.py

@@ -14,6 +14,6 @@ from .config import MilvusVectorIOConfig
 async def get_provider_impl(config: MilvusVectorIOConfig, deps: dict[Api, Any]):
     from llama_stack.providers.remote.vector_io.milvus.milvus import MilvusVectorIOAdapter
 
-    impl = MilvusVectorIOAdapter(config, deps[Api.inference])
+    impl = MilvusVectorIOAdapter(config, deps[Api.inference], deps.get(Api.files, None))
     await impl.initialize()
     return impl

llama_stack/providers/inline/vector_io/milvus/config.py

@@ -8,13 +8,24 @@ from typing import Any
 
 from pydantic import BaseModel
 
+from llama_stack.providers.utils.kvstore.config import (
+    KVStoreConfig,
+    SqliteKVStoreConfig,
+)
 from llama_stack.schema_utils import json_schema_type
 
 
 @json_schema_type
 class MilvusVectorIOConfig(BaseModel):
     db_path: str
+    kvstore: KVStoreConfig
 
     @classmethod
     def sample_run_config(cls, __distro_dir__: str, **kwargs: Any) -> dict[str, Any]:
-        return {"db_path": "${env.MILVUS_DB_PATH}"}
+        return {
+            "db_path": f"${{env.MILVUS_DB_PATH:={__distro_dir__}/milvus.db}}",
+            "kvstore": SqliteKVStoreConfig.sample_run_config(
+                __distro_dir__=__distro_dir__,
+                db_name=f"${{env.MILVUS_KVSTORE_DB_PATH:={__distro_dir__}/milvus_registry.db}}",
+            ),
+        }