Admin: Cal-ITP Benefits staff user can add new models

[angela-tran]

Acceptance Criteria

• The Benefits admin configuration is updated
  • Current model and field definitions
  • Confirm read/write permissions for each model field
• Cal-ITP Benefits staff users can create new instances of relevant models
  • ClaimsProvider
  • EnrollmentFlow
  • TransitAgency

Additional context

Part of #2001

[angela-tran]

Cal-ITP Benefits staff users can create new instances of EligibilityTypes, EligibilityVerifiers, AuthProviders, PaymentProcessors, and TransitAgencys

Some of these models have required fields that a Cal-ITP user wouldn't be able to set.

Cal-ITP users also currently wouldn't be able to add the templates / form classes for a new transit agency without engineers implementing those.

[thekaveman]

Cal-ITP Benefits staff users can create new instances of EligibilityTypes, EligibilityVerifiers, AuthProviders, PaymentProcessors, and TransitAgencys

Some of these models have required fields that a Cal-ITP user wouldn't be able to set.

Cal-ITP users also currently wouldn't be able to add the templates / form classes for a new transit agency without engineers implementing those.

#2471 addressed some of the concern with required fields and templates.

[thekaveman]

Let's confirm what if anything needs to be done to complete this. I think it might already be mostly done?