Refactor logic to determine which registration info to display

* Reduced amount of code and simplified it in order to make the code
more understandable and maintainable.
* If-else constructs are reduced to a minimum.
8 jobs for 180-use-case-for-event-registration-information in 5 minutes and 28 seconds (queued for 3 seconds)
Status Name Job ID Coverage
  Build
passed build:latest #159480

00:02:56

passed build:production #159483

00:01:48

passed build:production:review-apps #159482

00:03:11

passed build:production:subpath #159481

00:03:02

 
  Test
passed test:htmlproofer #159484

00:02:29

passed test:htmlproofer:subpath #159485

00:02:22

 
  Review
passed review #159486
review-apps

00:00:05

passed stop_review #159487
review-apps manual

00:00:01