vtk: 7.1.1 -> 8.2.0

- also create vtk_7 as several packages don't build with 8.x:
  - itk5: vtkVersion.h header not found at compile time
  - ants: version in tree (2.2.0) is incompatible with 8.2
  - itk4: ants depends on both vtk and itk4, so use vtk_7
  - gdcm: vtk header issue
  - python3Packages.vtk: Python C API compilation error with Python 3.8

- upgrade vtkWithQt4 -> vtkWithQt5

pkgs/top-level/python-packages.nix

@@ -7061,7 +7061,7 @@ in {
 
   visitor = callPackage ../development/python-modules/visitor { };
 
-  vtk = toPythonModule (pkgs.vtk.override {
+  vtk = toPythonModule (pkgs.vtk_7.override {
     inherit (self) python;
     enablePython = true;
   });