fix: rename llama_stack_api dir (#4155)

# What does this PR do?

the directory structure was src/llama-stack-api/llama_stack_api

instead it should just be src/llama_stack_api to match the other
packages.

update the structure and pyproject/linting config

---------

Signed-off-by: Charlie Doern <cdoern@redhat.com>
Co-authored-by: Ashwin Bharambe <ashwin.bharambe@gmail.com>

tests/unit/providers/utils/inference/test_openai_mixin.py

@@ -10,12 +10,12 @@ from typing import Any
 from unittest.mock import AsyncMock, MagicMock, Mock, PropertyMock, patch
 
 import pytest
-from llama_stack_api import Model, ModelType, OpenAIChatCompletionRequestWithExtraBody, OpenAIUserMessageParam
 from pydantic import BaseModel, Field
 
 from llama_stack.core.request_headers import request_provider_data_context
 from llama_stack.providers.utils.inference.model_registry import RemoteInferenceProviderConfig
 from llama_stack.providers.utils.inference.openai_mixin import OpenAIMixin
+from llama_stack_api import Model, ModelType, OpenAIChatCompletionRequestWithExtraBody, OpenAIUserMessageParam
 
 
 class OpenAIMixinImpl(OpenAIMixin):

tests/unit/providers/utils/inference/test_prompt_adapter.py

@@ -4,12 +4,11 @@
 # This source code is licensed under the terms described in the LICENSE file in
 # the root directory of this source tree.
 
-from llama_stack_api import OpenAIAssistantMessageParam, OpenAIUserMessageParam
-
 from llama_stack.models.llama.datatypes import RawTextItem
 from llama_stack.providers.utils.inference.prompt_adapter import (
     convert_openai_message_to_raw_message,
 )
+from llama_stack_api import OpenAIAssistantMessageParam, OpenAIUserMessageParam
 
 
 class TestConvertOpenAIMessageToRawMessage:

tests/unit/providers/utils/memory/test_vector_store.py

@@ -7,9 +7,9 @@
 from unittest.mock import AsyncMock, MagicMock, patch
 
 import pytest
-from llama_stack_api import URL, RAGDocument, TextContentItem
 
 from llama_stack.providers.utils.memory.vector_store import content_from_data_and_mime_type, content_from_doc
+from llama_stack_api import URL, RAGDocument, TextContentItem
 
 
 async def test_content_from_doc_with_url():

tests/unit/providers/utils/test_model_registry.py

@@ -34,9 +34,9 @@
 #
 
 import pytest
-from llama_stack_api import Model
 
 from llama_stack.providers.utils.inference.model_registry import ModelRegistryHelper, ProviderModelEntry
+from llama_stack_api import Model
 
 
 @pytest.fixture