boolean arrays incompatible with h5py

[ilia-kats]

HDF5.jl reads boolean arrays written by h5py as Int8 arrays. Apparently, h5py stores boolean arrays as HDF5 enums with names TRUE and FALSE by default. h5py's names can be changed at runtime](https://docs.h5py.org/en/latest/config.html), and h5py reads boolean arrays written using a different config as int8 arrays also.

The more serious issue is that boolean arrays as written by HDF5.jl are completely unknown to h5py and trigger an exception: TypeError: No NumPy equivalent for TypeBitfieldID exists.

[nhz2]

I think the issue of h5py not being able to read boolean arrays written by HDF5.jl was solved by h5py/h5py#1889