add support for v1/messages and transformations (#558)

* pushing draft PR

* transformations are working. Now need to add some tests next

* updated tests and added necessary response transformations for Anthropics' message response object

* fixed bugs for integration tests

* fixed doc tests

* fixed serialization issues with enums on response

* adding some debug logs to help

* fixed issues with non-streaming responses

* updated the stream_context to update response bytes

* the serialized bytes length must be set in the response side

* fixed the debug statement that was causing the integration tests for wasm to fail

* fixing json parsing errors

* intentionally removing the headers

* making sure that we convert the raw bytes to the correct provider type upstream

* fixing non-streaming responses to tranform correctly

* /v1/messages works with transformations to and from /v1/chat/completions

* updating the CLI and demos to support anthropic vs. claude

* adding the anthropic key to the preference based routing tests

* fixed test cases and added more structured logs

* fixed integration tests and cleaned up logs

* added python client tests for anthropic and openai

* cleaned up logs and fixed issue with connectivity for llm gateway in weather forecast demo

* fixing the tests. python dependency order was broken

* updated the openAI client to fix demos

* removed the raw response debug statement

* fixed the dup cloning issue and cleaned up the ProviderRequestType enum and traits

* fixing logs

* moved away from string literals to consts

* fixed streaming from Anthropic Client to OpenAI

* removed debug statement that would likely trip up integration tests

* fixed integration tests for llm_gateway

* cleaned up test cases and removed unnecessary crates

* fixing comments from PR

* fixed bug whereby we were sending an OpenAIChatCompletions request object to llm_gateway even though the request may have been AnthropicMessages

---------

Co-authored-by: Salman Paracha <salmanparacha@MacBook-Pro-4.local>
Co-authored-by: Salman Paracha <salmanparacha@MacBook-Pro-9.local>
Co-authored-by: Salman Paracha <salmanparacha@MacBook-Pro-10.local>
Co-authored-by: Salman Paracha <salmanparacha@MacBook-Pro-41.local>
Co-authored-by: Salman Paracha <salmanparacha@MacBook-Pro-136.local>

arch/envoy.template.yaml

@@ -526,13 +526,13 @@ static_resources:
               tls_minimum_protocol_version: TLSv1_2
               tls_maximum_protocol_version: TLSv1_3
 
-    - name: claude
+    - name: anthropic
       connect_timeout: 0.5s
       type: LOGICAL_DNS
       dns_lookup_family: V4_ONLY
       lb_policy: ROUND_ROBIN
       load_assignment:
-        cluster_name: claude
+        cluster_name: anthropic
         endpoints:
           - lb_endpoints:
               - endpoint: