fix(microsoft) get_avatar_url does not work

[arowley-ai]

Issue

This pull request fixes an with get_avatar_url for the Microsoft provider which as far as I can tell, does not work at all.

Solution

To fix the issue two additional requests were necessary. Firstly, to get a little metadata about the return type for the user photo and then to pull the user photo itself. I proposed a new setting that will enable/disable this behaviour as clearly we have the opportunity to save time for the majority of requests that do not need a user photo.

I chose to entirely replace the get_avatar_url method in the provider. That could be a little controversial since maybe somewhere out there somebody has an app that actually returns a valid URL but I am reasonably confident that this is not possible. As far as I can tell, the only endpoint from which any user photo can be accessed is via "https://graph.microsoft.com/v1.0/me/photo" and the only way to access the photo is as a binary stream (rather than a url).

The get_avatar_url method will provide a base64 encoded image stream directly instead of a url. I would have preferred the url option but apparently not with Microsoft. Nonetheless this solution will still render the image in place exactly as a valid url would. I think therefore that it is consistent with the original intent of this function but please let me know if you disagree.

To do

I am happy to update the documentation on this if it looks like something that can be accepted.

[coveralls]

coverage: 95.759% (-0.05%) from 95.805%
when pulling 80546d2 on arowley-ai:main
into ad89388 on pennersr:main.

[arowley-ai]

just fixed a little formatting