prepare_weights_double: issue when processed for different entries.

The following code is not handling the following use case:

• we process a first dataset XXX stored at fileA / entry0000.
  • -> this will create the file
• we process a second dataset YYY stored at fileA / entry0001
  • -> this will overwrite the existing file when it could / should created another entry.

This comes from the following lines:

def create_heli_maps(profile, process_file_name, entry_name, transition_width):
    profile = profile / profile.max()
    profile = profile.astype("f")

    profile = gaussian_filter(profile, 10)

    if os.path.exists(process_file_name):
        fd = h5py.File(process_file_name, "r+")
    else:
        fd = h5py.File(process_file_name, "w")