Configure sample California State Transit agency in `dev` and `test`

[thekaveman]

:construction: this issue is still being scoped :construction:

We've reached a point of stability in the Admin interface, and also a point where we need to be able to demo and test in-progress enrollment flows that don't necessarily have a representative agency (yet!).

All along, our designs have included a fictitious agency CST (or the California State Transit agency) used for mocking, spacing, etc.

This task is about configuring the app in both dev and test with a TransitAgency instance and the related data for CST.

Acceptance Criteria

Code:

• [ ] #2197
• [ ] benefits/core/migrations/local_fixtures.json refactored to remove "real" agency samples and replace with CST
• [ ] Cypress tests updated to reflect changes to "out of the box" app

dev and test configuration:

• [ ] New EligibilityType instances are created
  • [ ] Older Adult: use CST success template
  • [ ] CalFresh Cardholder: use CST success template
  • [ ] US Veteran: use CST success template
  • [ ] Agency Card: use CST Agency Card success template
• [ ] New EligibilityVerifier instances are created
  • [ ] Age claims via Login.gov
  • [ ] CalFresh claims via CA Department of Social Services
  • [ ] Veteran claims via VA.gov
  • [ ] Eligibility server verifier (copy from MST)
• [ ] A new PaymentProcessor instance is created
  • [ ] Exact configuration TBD
• [ ] A new TransitAgency instance is created
  • [ ] slug: cst
  • [ ] short name: CST
  • [ ] long name: California State Transit
  • [ ] agency id: cst
  • [ ] info_url: https://www.agency-website.com
  • [ ] phone: 1-800-555-5555
  • [ ] active: true