Implement HDF5 file reader class

Closes L2SS-1063

lofar_station_client/file_access/__init__.py

+#  Copyright (C) 2022 ASTRON (Netherlands Institute for Radio Astronomy)
+#  SPDX-License-Identifier: Apache-2.0
+
+
+"""
+Contains classes to interact with (hdf5) files
+"""
+
+from ._hdf5_member_def import member
+from .file_reader import Hdf5FileReader, read_hdf5
+
+__all__ = ["Hdf5FileReader", "member", "read_hdf5"]