Update docstrings

Docstrings to update

- database_manage.py, insert_date function : In args, update list of tables accepted

Current : table_name (str): The name of the target table. Supported values are "directories", "cnil", "constit", and "legi".
New : table_name (str): The name of the target table. Supported values are "directories", "cnil", "constit", "legi", "jade", "bofip".

- _get_length_function