feat(provider): add AzureAD provider

[MarvinZeising]

What:

Add new provider: Azure Active Directory

Why:

Spent quite some time on trying to get it to work with the Azure Active Directory B2C provider.
Ended up using this as my custom provider.
I think having a separate provider for that should make this a lot easier for other devs.

How:

Checklist:

• Documentation
• Tests N/A
• Ready to be merged

[vercel]

This pull request is being automatically deployed with Vercel (learn more).
To see the status of your deployment, click below or on the icon next to each commit.

🔍 Inspect: https://vercel.com/nextauthjs/next-auth/DWSMjFbADB6k97ZdgnxwyKk9D231
✅ Preview: https://next-auth-git-fork-marvinzeising-feat-azure-ad-nextauthjs.vercel.app

[balazsorban44]

There is already a PR similar to this at #1591, is this one different from that?

[balazsorban44]

Closing as I think it is a duplicate of #1591. Feel free to Re-open if I'm wrong.

[MarvinZeising]

@balazsorban44 Sorry for my late reply.

I don't know if the one in #1591 works.
At least for me, it didn't work without the params.grant_type, headers.Origin, and protection properties.
Also, IMHO, his approach seems to be a lot more complicated.

But you're definitely right - this one is a duplicate. Sorry.