feat: replace enterprise logistration logic with openedx-filters hooks

Replace the enterprise-specific logic in the user_authn logistration
views with six generic filters, removing all enterprise_support
imports and enterprise-specific logic:

- LogistrationViewContextGenerated
- AuthnMFEContextGenerated
- LogistrationViewRenderCompleted
- LoginFormGenerated
- RegistrationFormGenerated
- LoginAltRedirectURLRequested

ENT-11568