Remove own Compressor classes and instead rely on hdf5plugin Filter objects.

enstools/encoding/compressors/api.py

enstools/encoding/compressors/blosc.py

enstools/encoding/compressors/compressor_class.py

enstools/encoding/compressors/no_compressor.py

enstools/encoding/compressors/sz.py

enstools/encoding/compressors/zfp.py

enstools/encoding/encodings.py

requirements.txt