In `test_contained_in` and other tests, assert more data instead of just the `passed` key

Is your feature request related to a problem? Please describe.
Not related to functionalities of the program, only to make the testcases more robust and reliable.

Describe the solution you'd like
Most of the test cases only assert the passed key and not all of the key, it's best to actually assert most of the keys available so that we know between evaluation that is actually failing or is not evaluated.
One example of this would be in test_contained_in

@mark.passing
@mark.parametrize("evaluator_input,evaluator_data", checks_passing)
def test_evaluate_passing(evaluator_input, evaluator_data):
    result = evaluator.evaluate(evaluator_input, evaluator_data)
    assert result["passed"] == True  # {"passed": True, "message": f"Found {evaluator_input} inside {evaluator_data}"}

We have to at least assert as well the message key.

Start by locating test_contained_in and the test_evaluate_passing case shown in the issue, then inspect the evaluator results and checks_passing data used there. Extend the assertions beyond passed, including message and other keys exposed by the test data, and run the affected tests to confirm failures distinguish evaluation from assertion problems.