Typos in VolumeSingleFrameBase class attributes

The class VolumeSingleFrameBase uses names with a repeated DATA_DATA pattern:

class VolumeSingleFrameBase(VolumeBase):

    DEFAULT_DATA_DATA_PATH_PATTERN = "{volume_basename}_{index_zfill4}.{data_extension}"

    [...]

    DEFAULT_METADATA_DATA_PATH_PATTERN = "{volume_basename}_infos.{metadata_extension}"

I think it would be better to use DEFAULT_DATA_PATH_PATTERN.

Also in tomoscan/esrf/volume/hdf5volume.py: DATA_DATASET_NAME, perhaps would be better with DATASET_NAME (less sure about this one)