ITKVtkGlue only requires parts of ITK

Only the required ITK modules (most likely only itk-common) should be listed in the Python requirements of ITKVtkGlue, so that people using the package do not have to install the whole ITK Python package. This is especially relevant when packaging a Python script with PyInstaller where all the dependencies are embedded in one file.

Relevant line of code to change:
https://github.com/InsightSoftwareConsortium/ITKVTKGlue/blob/master/setup.py#L47