Azure single tenant support

[CrutchTheClutch]

- Summary

This pull request is not complete as I am very inexperienced in golang and have not had time to fully flesh this out. But, I wanted to get it started as it's a big blocker for utilizing supabase for internal tools through Azure.

- Test plan

N/A - Incomplete pull request

- Description for the changelog

Adds tenant_id parameter to azure oauth provider that defaults to "common". Should support the possibility for single tenancy with azure

- A picture of a cute animal (not mandatory but encouraged)

[CrutchTheClutch]

Well, I feel silly! I meant to merge this into https://github.com/supabase/gotrue 😅 Apologies!