Auth: Azure AD OAuth (#20030)

* Implement Azure AD oauth

* Use go-jose and cleanup

* Update go-jose in go.mod

* cleanup

* Add unit tests

* Fix scopes

* Add documentation page

* Improve documentation

* Convert extract_role into function.

* Do not use upn and replace unique_name with preferred_username

* Configure login button

* Use official microsoft icon and color from branding guideline.

* Add Azure AD config section in sample.ini.

docs/sources/menu.yaml

@@ -39,6 +39,8 @@
       name: Generic OAuth
     - link: /auth/google/
       name: Google
+    - link: /auth/azuread/
+      name: Azure AD
     - link: /auth/github/
       name: GitHub
     - link: /auth/gitlab/