Also extend unit-test to use new test helper functions.
Remove the now-redundant test for three-way comparison, because it is
covered by the test helper functions.
Task-number: QTBUG-117661
Change-Id: I242b560c281245e04e34353c80000a20998fc677
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>
Reviewed-by: Qt CI Bot <qt_ci_bot@qt-project.org>