Bug#1029285: vtk9: build the IO/GeoJSON module

[Drew Parsons]

Package: vtk9
Version: 9.1.0+really9.1.0+dfsg2-4+b3
Severity: normal
Control: affects -1 src:vedo

vtk9 has a IO/GeoJSON module, but it's not built by default.
Is it possible to add it to the build?

The reason is that vedo provides geojson support via vtk's python
module vtkmodules.vtkIOGeoJSON.  We have to hack vedo if vtk is not
providing it.

If I got the right sense of the vtk configuration, what's needed is to
add
  -DVTK_MODULE_ENABLE_VTK_IO_GEOJSON=YES
It's possible that's not the right syntax, the VTK documentation is
not so clear.