MS Graph API Copilot API Support

## Category

- [x] Feature request

## Describe the feature

We should support Copilot API in the SDK
https://learn.microsoft.com/en-us/microsoft-365/copilot/extensibility/api/ai-services/retrieval/overview

## Describe the solution you'd like

I would love to be able to call the Copilot API from the SDK and later from PnP.PowerShell

## Additional context
