Fixed two "random lines twice" workflow errors.
- DemonstrationWorkflowEngine: fixed error in the selectRandomLines method when trying to randomly select more lines than there are available.
- RandomLinesExample: now log the correct expected number of lines in the checkWorkflowOutput method.
- BaseGuiExample: added workflow failure message and workflow duration to the logging in the runRandomLinesWorkflow method.
- BaseExample: added getter and field for the workflow duration.