SIM-862: update the pycraf and oskar scripts to allow for h5 files
I updated the oskar_sim_beam_gain_sing.py
to keep original functionality but to also allow for reading data from and writing to HDF5 files. This resulted in some code duplication, which is deliberate: makes it easier to delete old version when we decide to fully transition the scripts to h5.
The changes to the RASCIL-based script will be part of a next MR. --> UPDATE: RASCIL needs a bit of refactor (not just the sim-low code), so we'll push this bit to next PI.
Edited by Gabriella Hodosán