Microsoft for Sovereignty clouds

[jimseiwert]

Goals

1. allow users to specify additional Microsoft cloud for login such as .us vs .com

Non-Goals

1. list of all possible cloud offerings

Background

Microsoft has several different cloud endpoints depending on offerings being used. To authenticate against these you need to change your endpoints as such. This PR is an extension of the initial offering for Microsoft Entra authentication. #9154 (comment).

Additional endpoints can be seen here: https://learn.microsoft.com/en-us/graph/deployments

Proposal

I propose we add an additional environment variable called AUTH_MICROSOFT_ENTRA_ID_BASE_URL with a default value of https://login.microsoftonline.com. If the user specifies a different endpoint we will use that value.

This will maintain backwards compatibility and allow for future expansion. Happy to submit a PR to support.