chore: Consistent naming for VectorIO providers (#1023)

# What does this PR do?

This changes all VectorIO providers classes to follow the pattern
`<ProviderName>VectorIOConfig` and `<ProviderName>VectorIOAdapter`. All
API endpoints for VectorIOs are currently consistent with `/vector-io`.

Note that API endpoint for VectorDB stay unchanged as `/vector-dbs`. 

## Test Plan

I don't have a way to test all providers. This is a simple renaming so
things should work as expected.

---------

Signed-off-by: Yuan Tang <terrytangyuan@gmail.com>

llama_stack/providers/remote/vector_io/sample/__init__.py

@@ -6,12 +6,12 @@
 
 from typing import Any
 
-from .config import SampleConfig
+from .config import SampleVectorIOConfig
 
 
-async def get_adapter_impl(config: SampleConfig, _deps) -> Any:
-    from .sample import SampleMemoryImpl
+async def get_adapter_impl(config: SampleVectorIOConfig, _deps) -> Any:
+    from .sample import SampleVectorIOImpl
 
-    impl = SampleMemoryImpl(config)
+    impl = SampleVectorIOImpl(config)
     await impl.initialize()
     return impl

llama_stack/providers/remote/vector_io/sample/config.py

@@ -7,6 +7,6 @@
 from pydantic import BaseModel
 
 
-class SampleConfig(BaseModel):
+class SampleVectorIOConfig(BaseModel):
     host: str = "localhost"
     port: int = 9999

llama_stack/providers/remote/vector_io/sample/sample.py

@@ -7,11 +7,11 @@
 from llama_stack.apis.vector_dbs import VectorDB
 from llama_stack.apis.vector_io import VectorIO
 
-from .config import SampleConfig
+from .config import SampleVectorIOConfig
 
 
-class SampleMemoryImpl(VectorIO):
-    def __init__(self, config: SampleConfig):
+class SampleVectorIOImpl(VectorIO):
+    def __init__(self, config: SampleVectorIOConfig):
         self.config = config
 
     async def register_vector_db(self, vector_db: VectorDB) -> None: