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/build_mpi_complete_vtk9.sh

@@ -2,7 +2,7 @@
 set -exo pipefail
 source $(cd "$(dirname "$0")"; pwd -P)/ci_funcs.sh
 
-dot -v
+#dot -v
 
 # load MPI environment
 load_MPI