Add ADIOS example Datasets

[C0nsultant]

For reference purposes, it would be convenient to have (validated) sample files in formats other than HDF5.

This also should uncover possible incompatabilities and inconsistencies between file formats (e.g. HDF5 and ADIOS lack bool due to their C roots, see openPMD/openPMD-api#50).

ADIOS is a major backend in the community and thus should deserve some attention. As the author of openPMD/openPMD-api#126, it was difficult to verify file correctness without any ground thruth.

[ax3l]

there are some linked here: #3 (comment)

but I guess they are still a bit large.

[C0nsultant]

If we trust the openPMD-api enough, we can generate files from that (talk about a chicken-and-egg problem).

I'll see if I can come up something creative that goes beyond particle-mesh data, as that still is compatible with openPMD.
If you want something more in your domain, you could point me to some code that I can use.

[ax3l]

If you want to run our slacky, hand-written PIConGPU implementation: https://picongpu.readthedocs.io/en/latest/ PIConGPU runs on CPUs :) I probably won't have time for this in the next weeks, though :(