streaming support for ReActAgent

[tom-leamon]

Streaming for OpenAIAgent was added by #788. Attempting to use AnthropicAgent results in the error:

Error: Anthropic does not support streaming

This Error message is a little dubious, because it's clear Anthropic does actually support streaming, so I assume this to be a limitation of the current implementation of agent streaming, in which case the error should be:

Error: LlamaIndex does not yet support streaming for AnthropicAgent

Additionally, I attempted to use ReActAgent streaming with Llama3-70B on Groq. The call seemed to just freeze and never return any results.

Non-streaming works properly for both AnthropicAgent and ReActAgent. I would like to clarify if these are just limitations of the current agent streaming abilities, or if it's actually true that this is not possible with Anthropic.

[himself65]

1. Anthroipc doesn't support streaming https://docs.anthropic.com/claude/docs/tool-use

[himself65]

Thanks for report, seems like there is a bug in ReAct Agent that will exit silently

[himself65]

Seems like a pitfall