ENH: add example of manipulating contents of web view

In this example the qt qpi is used to manipulate the DOM of a loaded
web page. In this case, we add a search string into a form, but the
concept could be generalized to allow exchange of data between slicer
and any web-based system that doesn't expose a clean web services api.

git-svn-id: http://svn.slicer.org/Slicer4/trunk@22079 3bd1e089-480b-0410-8dfb-8563597acbee