python API: Dask Compatible

[ax3l]

Idea for the future:

When we read data in the python API, we should make sure this is compatible and possible to be distributed for compute tasks inside dask. See the hdf5 read example within. (Similar to pyDive, but more powerful.)

[ax3l]

Part of 0.14.0+ 🎉

X-ref: #952 #958 #959 #951 #963 et al. :)