- add StreamEven API domain model for reliably parsing stream events.
- add StreamHelper#mergeToolUseEvents to aggregate partial tool use jsons into a list of ContentBlocks.
- add StreamHelper#eventToChatCompletionResponse to convert Flux<StreamEvents> into Flux<ChatCompletionResponse>.
- Rename MediaContent -> ContentBlock, RequestMessage -> AnthropicMessage, ChatCompletion -> ChatCompletionResponse.
- Improve tests and docs.