ENH: allow wordHashSet filter for IOobjectList::names

- simplifies usage.
  Support syncPar check on names() to detect inconsistencies.

- simplify readFields, ReadFields and other routines by using these
  new methods.

applications/utilities/postProcessing/graphics/PVReaders/vtkPVFoam/vtkPVFoamFields.C

@@ -194,7 +194,6 @@ void Foam::vtkPVFoam::convertAreaFields()
     // Get objects (fields) for this time - only keep selected fields
     // the region name is already in the mesh db
     IOobjectList objects(mesh.mesh(), dbPtr_().timeName());
-
     objects.filterKeys(selectedFields);
 
     if (objects.empty())