Updated BB Code tests to be more informative. And made them pass.

- While test was expecting a validation error, it was not handling exceptions
 from WebDriver layer and therefore it would fail. Added exception handling.
- Added a logging of the case that fails - previously if the test fails, nothing
 would be logged.
- Topics that are created while test execution now have a meaningful part in
 their title so that it's easier to distinguish them if they fail and you watch
 a video record. Also random part was added so that titles differ.