rest_views/RunConfigViewSet: enable fetching runconfig by name
Actually in other runconfig endpoints like "compare" or "known_failures" we can already identify runconfig by name, so let's reuse present code to enable fetching runconfigs by name.
Actually in other runconfig endpoints like "compare" or "known_failures" we can already identify runconfig by name, so let's reuse present code to enable fetching runconfigs by name.