Testers wanted: Teams chats, Outlook shared mailboxes

Microsoft365R has been updated with the following features:

- Add support for shared mailboxes to `get_business_outlook()` (#39). To access a shared mailbox, supply one of the arguments `shared_mbox_id`, `shared_mbox_name` or `shared_mbox_email` specifying the ID, displayname or email address of the mailbox respectively.
- Add support for Teams chats (including one-on-one, group and meeting chats).
- Use the `list_chats()` function to list the chats you're participating in, and the `get_chat()` function to retrieve a specific chat.
- A chat object has class `ms_chat`, which has similar methods to a channel: you can send, list and retrieve messages, and list and retrieve members/attendees. One difference is that chats don't have an associated file folder, unlike channels.
- Updated the app permissions for Sharepoint to fix an access issue

However, at the moment I don't have access to a suitable tenant for testing these. **This is a request for anyone whose tenant has approved the Microsoft365R app registration to install the development version and try using these features.**

If you have previously used OneDrive, Teams and Outlook, everything should still work the same as before.

If you previously tried to use Sharepoint and got an authentication error, you should see a screen requesting you to grant Microsoft365R permission to access your Sharepoint site. You may or may not need an admin to approve the request, depending on your tenant's policies.

Use a tenant where the Microsoft365R app registration is approved, install the development version, and exercise get_business_outlook() with shared_mbox_id, shared_mbox_name, or shared_mbox_email. Run list_chats() and get_chat() to check chat retrieval and related message/member operations, and retry SharePoint access to verify the permission change. Done means these features work and any failures are reported with tenant details.

Written by the indexing model from the issue text.