Todo: Python example chatbot support for OAuth-based MCP servers

Currently the Python example chatbot will not communicate with OAuth-based MCP servers.

Implementation is blocked on this issue:
https://github.com/modelcontextprotocol/python-sdk/issues/1054

I have a draft implementation ready here, once that issue is resolved:
https://github.com/awslabs/run-model-context-protocol-servers-with-aws-lambda/tree/python-oauth-client