translator: toolCalls support in OpenAI to Bedrock

[wengyao04]

In this PR, I improve the translator to handle toolCalls. If toolCalls is not in the OpenAI message we append toolResultBlock for assistant role message. In the Response body, we add toolCalls if bedrock content has toolUse

I also refactor openAIMessageToBedrockMessage to have separate functions to convert message for different roles user, assistant, system and tool.

When dealing with image content in the roles message, add a function to parse data uri and add proper error handling.

[mathetake]

Could you shorten the title so that it fits in the commit title

[wengyao04]

@wengyao04 @yuzisun i guess the items list PR description might be a BB style but could you from now write messages in sentences? (i will add a PR template later, but for now could you follow my PR like #135)

Update the commit message with readable paragraph.

[mathetake]

thanks for the multiple iterations. style wise LGTM, so deferring to @yuzisun for the actual logic final approval

[wengyao04]

thanks for the multiple iterations. style wise LGTM, so deferring to @yuzisun for the actual logic final approval

Thanks you for helping review, I will send another PR to add ToolCalls support in converse stream

[yuzisun]

The finish reason here should be “tool_calls” as the stop reason on ConverseOutput is set to toolUse in this case.

[wengyao04]

update the unit test, for input bedrock converse response, the stop reason is tool_use for content with toolUseBlock. The output openai chat completion stop reason is expected to be tool_calls

[yuzisun]

Thanks @wengyao04 !!