Resolve "Move to dask for loading hdf5 arrays"

What does this MR do?

This MR implements the possibility to load hdf5 datasets via dask. This is achieved through a flag in the HDFDataProxy named resolve_as_dask. If true, the hdf5 file is loaded as a h5py.Dataset object which is directly passed to the dask.array.from_array() function. The load_hdf5 method now takes proxy_kwargs in which the resolve_as_dask parameter can be set.

Can this MR be accepted?

• Renamed ProxyMixin to ProxySupportMixin
• Implemented the resolve_as_dask functionality into the HDFDataProxy.
• Adapted the load_hdf5 function to take proxy_kwargs
• Tests added
• Full test coverage
• Pipeline passes
• Changelog entry added
• Version bumped to 0.8.0rc1
• Approved by @blsqr

Anything to double-check?

Related issues

Closes #27 (closed)