Adapt to NVIDIA IndeX binaries for ParaView 6.0.
This MR adapts the superbuild to a new NVIDIA IndeX release that we will share soon.
[DONE] As usual, the filenames and MD5 hashes of the "nvidia-index-libs-*.tar.bz2" tarballs still need to be updated once the packages have been generated with /home/jmensmann/paraview-superbuild/
Scripts/index/extract-index.sh`. There will also be a separate MR for the main ParaView repo.
[DONE] "DEFAULT" also still needs to be adapted.
SPDX license/copyright information in nvidiaindex.cmake was updated and adapted to the third-party license in pvNVIDIAIndeX-license.txt. Some of the licenses previously listed in nvidiaindex.cmake were not actually part of the NVIDIA IndeX package that is shipped with ParaView (e.g. font files, JavaScript libararies, glew).
@ben.boeckel @mwestphal: FYI