standard-tests[patch]: Update chat model standard tests (#22378)

- Refactor standard test classes to make them easier to configure
- Update openai to support stop_sequences init param
- Update groq to support stop_sequences init param
- Update fireworks to support max_retries init param
- Update ChatModel.bind_tools to type tool_choice
- Update groq to handle tool_choice="any". **this may be controversial**

---------

Co-authored-by: Chester Curme <chester.curme@gmail.com>

libs/partners/mistralai/tests/unit_tests/test_standard.py

@@ -2,7 +2,6 @@
 
 from typing import Type
 
-import pytest
 from langchain_core.language_models import BaseChatModel
 from langchain_standard_tests.unit_tests import ChatModelUnitTests
 
@@ -10,6 +9,6 @@ from langchain_mistralai import ChatMistralAI
 
 
 class TestMistralStandard(ChatModelUnitTests):
-    @pytest.fixture
+    @property
     def chat_model_class(self) -> Type[BaseChatModel]:
         return ChatMistralAI