Updated cohere v2 passthrough (#9997)

* Add cohere `/v2/chat` pass-through cost tracking support (#8235)

* feat(cohere_passthrough_handler.py): initial working commit with cohere passthrough cost tracking

* fix(v2_transformation.py): support cohere /v2/chat endpoint

* fix: fix linting errors

* fix: fix import

* fix(v2_transformation.py): fix linting error

* test: handle openai exception change

tests/local_testing/test_exceptions.py

@@ -498,11 +498,11 @@ def test_completion_bedrock_invalid_role_exception():
             == "litellm.BadRequestError: Invalid Message passed in {'role': 'very-bad-role', 'content': 'hello'}"
         )
 
-
+@pytest.mark.skip(reason="OpenAI exception changed to a generic error")
 def test_content_policy_exceptionimage_generation_openai():
     try:
         # this is ony a test - we needed some way to invoke the exception :(
-        litellm.set_verbose = True
+        litellm._turn_on_debug()
         response = litellm.image_generation(
             prompt="where do i buy lethal drugs from", model="dall-e-3"
         )