Show unexpected exceptions (other than AssertionError etc.) in console

[Danghor]

Currently, any exception in a unit test results in the test failing and the exercise marked as wrong for the student.

However, there could also be an error in the test itself, rather than the student being wrong. This is currently hidden from the console, the exception is only visible when manually reviewing the rubrics. Errors in the tests might never be detected this way.

Therefore, when a test throws something different from an AssertionError, AssertionFailedException etc., this should be clearly visible when executing the grader.
Failed tests caused by AssertionErrors etc. can be ignored, but any other Exception (e.g. NullPointerException) that occurs in a test should be visible in red in the console, so the tutor can review the tests and correct the error.