refactor: run C3 e2e tests more easily locally and individually

[petebacondarwin]

• Tests
  • [ ] TODO (before merge)
  • [x] Tests included
  • [ ] Tests not necessary because:
• Wrangler / Vite E2E Tests CI Job required? (Use "e2e" label or ask maintainer to run separately)
  • [ ] I don't know
  • [ ] Required
  • [x] Not required because: c3
• Public documentation
  • [ ] TODO (before merge)
  • [ ] Cloudflare docs PR(s):
  • [x] Documentation not necessary because: test refactor
• Wrangler V3 Backport
  • [ ] TODO (before merge)
  • [ ] Wrangler PR:
  • [x] Not necessary because: c3