Integrate vtk9

Integrate the VTK 9 patches and generate a suitable docker container to test.

TODO:

• upload container to registry
• add gitlab-ci entry to run it

ci/ci_funcs.sh

 # make sure profile is really loaded
 source /etc/profile
-source /etc/profile.d/z10_spack_environment.sh
 
 # create a badge in current directory
 function create_badge {