Migrate ParaViewWeb widgets into more generic VTK ones

Change-Id: I9ed311236e82aee369a451a35848068ee4b648f8
Add basic url parameter extractor within vtkWeb

Change-Id: I5498dd2cb4327ce7ea63e56a2ef24b0076adac98
Add server side FileBrowser

This add a new vtkWeb widget to deal with server side browsing.

Change-Id: Id78b12c13eb20b2a64f9b82fa90ebbe02a4fd338
Merge topic 'vtkweb-add-file-widgets' into master

7087e30c Add server side FileBrowser
3a2d3f71 Add basic url parameter extractor within vtkWeb
5611f9cb Migrate ParaViewWeb widgets into more generic VTK ones