Cannot save EligibilityVerifier without providing an AuthProvider

[angela-tran]

(Prompted by post-merge steps for #1970)

Intended behavior is that an EligibilityVerifier can exist without an AuthProvider. However, currently it is not possible to save one in that state from the admin interface.

The reason why we have existing EligibilityVerifiers with no auth_provider is because they were created externally rather than through the admin interface (see #1856 for notes on that process).

To Reproduce

Steps to reproduce the behavior:

1. Go to /admin
2. Log in
3. Click on "Eligibility verifiers"
4. Choose an eligibility verifier that does not have an auth provider
5. Go into the form for editing it
6. Update some field (e.g. Name)
7. Click "Save"
8. Notice error saying the Auth provider field is required

Expected behavior

The eligibility verifier is saved with the update you made.

Screenshots

Expand to see

Additional context

• Current field definition: auth_provider = models.ForeignKey(AuthProvider, on_delete=models.PROTECT, null=True)
• Django docs:
  • Field.blank
  • Field.null
  • ForeignKey.on_delete

Whether as a part of this issue or a separate one, we should go through and make sure all our model fields work as intended from the admin interface.

[angela-tran]

I was able to save a verifier without needing to have an auth provider 🎉

This allowed me to set help_template for MST and SBMTD agency card flows on dev, which finishes out the post-merge steps from #1970 ✔️

Whether as a part of this issue or a separate one, we should go through and make sure all our model fields work as intended from the admin interface.

Done for all model fields