ENH: Display module name in qSlicerCLIProgressBar

This commit allows to display the name of the CLI module node in
the top left corner of the progressbar. This new feature follows
the same implementation than for the status visibility and the
progressbar visibility. By default the CLI Module node name is
always hidden.

Rational :

When creating a python module running a pipeline of CLI modules,
we usually link our main progressbar to the current CLI node.
This practice helps following the progress of one module, but was
lacking information regarding our progress in the whole pipeline.
Displaying the name of the CLI module node above the progressbar
allows for more explicit information.

From: Alexis Girault <alexis.girault@kitware.com>

git-svn-id: http://svn.slicer.org/Slicer4/trunk@24537 3bd1e089-480b-0410-8dfb-8563597acbee