Add list of test case failures

**How would you describe the topic that you would love to see in the documentation?**
On the "How to test" page, there is a todo about failing test cases. We should create such a list.

**On which page or to which section does this belong?**
Tutorials -> How to test

**Can you reference a related GitHub repository or source code?**
N/A

**Additional context**
N/A
