Add an end-to-end test for the formatter

[nielsdebruin]

What's changed?

This PR adds an end-to-end test, which will test the full auto-formatted for a mix of formatting tasks to ensure that the visitors will work correctly together. The test still fails, which is to be accepted as the formatter needs some extra fixes.

What's your motivation?

Anything in particular you'd like reviewers to focus on?

Anyone you would like to review specifically?

Have you considered any alternatives or workarounds?

Any additional context

Checklist

• I've added unit tests to cover both positive and negative cases
• I've read and applied the recipe conventions and best practices
• I've used the IntelliJ IDEA auto-formatter on affected files