- Don't manage the progress anymore in the QtWigetView
      - Make the QtWidgetModel emitting all the signals (start reporting progress,
        reset the widgets...)
      - Create the layout once to avoid Qt warnings
      - Use the itkQtProgressBar that emit the signal relative to the ProgressEvent
        to update the ProgressBar in the application

ENH: refactor the widget creation in QWidget children, fuse factories in ParameterFactory.cxx, add choice and string + tests