Function calling for chat bots

[cgillum]

Context

OpenAI's chat API supports function calling. This is a way to connect GPT's capabilities with external tools and APIs.

Proposal

Add function calling support to chat bots created by this extension. The bot should be able to invoke other functions defined in the same Function app. For example, a function could be defined that does an internet search and the chat bot should be able to invoke that function when appropriate.

For functions that could be considered dangerous (such as making calls to authenticated APIs) it should be possible to have the chat bot request permission from the user before performing the action.