Use stage and phase attempt counters when saving test artifacts
    
    Azure Pipelines provide counters for running test jobs, these split into
    System.StageAttempt and System.PhaseAttempt. Use them to make test
    artifacts unique.
    
    For XML test results we don't need to name them differently as they
    aren't uploaded as artifacts but rather presented in a separate test
    pane.
    
    Reviewed-By: Florence Blanc-Renaud <flo@redhat.com>
    Reviewed-By: Stanislav Levin <slev@altlinux.org>