fix(auth): ensure users are created using emails as returned from azu…

…re (#964)

* fix: ensure user emails are lowercase when saved to postgres

azure was returning emails with cases that had changed and it broke user access

* fix: override AzureBackend and AuthHandler.authenticate to lower emails

* revert users/helper.py

* fix(auth): retain case in email used to create user

weve removed the `normalize_email` method from our CustomUserManager

this was causing issues when emails in users_customuser did not match emails returned from azure

where `normalize_email` would lowercase the domain of an email

* revert path to auth backend

users/managers.py

@@ -15,7 +15,6 @@ def create_user(self, email, **extra_fields):
         if not email:
             raise ValueError(_("The Email must be set"))
 
-        email = self.normalize_email(email)
         user = self.model(
             email=email,
             **extra_fields,