Add Microsoft Group Sync Worker

What does this MR do and why?

Related to #414873 (closed)

This extends the existing SAML Group Sync feature to also support Microsoft Azure AD. This is a necessary addition because Azure will send an overage claim if a user is a member of more than 150 groups. See https://learn.microsoft.com/en-us/security/zero-trust/develop/configure-tokens-group-claims-app-roles#group-overages.

This pulls some logic out of SAML group sync class into a base class so we can re-use as much as possible.

Risk: Because I pulled shared logic out of the existing SAML Group Sync worker, there's a slight possibility we cause a regression. Reviewers should take special care when reviewing the changes to the existing worker class. The new worker, however, won't be used yet.

Screenshots or screen recordings

Screenshots are required for UI changes, and strongly recommended for all other merge requests.

Before	After

How to set up and validate locally

Numbered steps to set up and validate the change are strongly suggested.

This is unfortunately difficult to test locally at this stage. In the final MR, when I add documentation and the ability to configure the settings in the UI, the docs will serve as a good list to set this up locally. I will encourage the reviewers to do so at that time. Until then, this won't be used.

MR acceptance checklist

This checklist encourages us to confirm any changes have been analyzed to reduce risks in quality, performance, reliability, security, and maintainability.

• I have evaluated the MR acceptance checklist for this MR.