Add support for national clouds to the Azure / Entra ID providers

[calebhansard]

Goals

1. Support Microsoft Entra national clouds by allowing the user to override the issuer and graph URLs

Non-Goals

No response

Background

The azure-ad and entra-id providers use fixed URLs for the issuer and Microsoft Graph endpoints, which prevents their use in Microsoft Entra national clouds

Proposal

Add new configuration options to the Azure AD / Entra ID providers to support custom issuer and Microsoft Graph endpoints.

Example endpoints

issuer: https://login.microsoftonline.us
graph: https://graph.microsoft.us