add free plan (#549)

- add new fields to support this
- when free:
  - fade out all event types after first
  - hide events after first on booking page
  - make booking page after the first one 404 if accessed directly
- add e2e tests

.github/workflows/e2e.yml

@@ -66,3 +66,4 @@ jobs:
           name: videos
           path: |
             cypress/videos
+            cypress/screenshots