Tests: cleanup resources used by Omni Core after testing
Tests: cleanup resources used by Omni Core after testing

Omni Core may, or may not be initialized during the tests, and this guarantees no resources remain as leftover..

In particular there was a case where Omni Core specific folders could not be removed from the temporary test dir, because some files were still locked, which resulted in an exception.

OmniLayer/omnicore,OmniLayer/omnicore,OmniLayer/omnicore,OmniLayer/omnicore,OmniLayer/omnicore,OmniLayer/omnicore