The purpose of this file is to state changes that where made to the dataset reader
and further files taken from https://github.com/boschresearch/mulms-az-codi2023.

Changes:

- The file mulms.py originates from source/data_handling/mulms_dataset.py
- The constants SENT_TYPE, MATSCI_SENT_TYPE, TOKEN_TYPE, SKIPPING_TYPE,
  ENTITY_TYPE, RELATION_TYPE, PASSAGE_TYPE and DOCUMENT_METADATA_TYPE were
  added to mulms.py from source/constants/constants.py
- The functions get_token_indices_for_annot(), get_token_index_for_annot_if_subtoken()
  were added to mulms.py from source/data_handling/util.py
- The variables az_content_labels, az_structure_labels, meas_labels, mulms_ne_labels, rel_labels,
  ne_labels_set, all_az_labels, meas_labels_set and rel_label_set were added to mulms.py
  from source/constants/constants.py