Create missing folders if needed

Refs https://redmine.teklia.com/issues/7377

To avoid this error when the folder /home/training_data/ATR_page/Aurexus/aurexus_page_sem doesn't exist

$ teklia-dan dataset entities \
    /home/training_data/ATR_page/Aurexus/aurexus-dossiers-de-pensions-militaires-20240521-083117.sqlite \ 
    --output-file /home/training_data/ATR_page/Aurexus/aurexus_page_sem/entities.yml

Traceback (most recent call last):
  File "/home/users/mblanco/dev/dan/bin/teklia-dan", line 8, in <module>
    sys.exit(main())
  File "/home/users/mblanco/dev/dan/dan/cli.py", line 31, in main
    status = args.pop("func")(**args)
  File "/home/users/mblanco/dev/dan/dan/datasets/entities/extract.py", line 21, in run
    output_file.write_text(
  File "/usr/lib/python3.10/pathlib.py", line 1154, in write_text
    with self.open(mode='w', encoding=encoding, errors=errors, newline=newline) as f:
  File "/usr/lib/python3.10/pathlib.py", line 1119, in open
    return self._accessor.open(self, mode, buffering, encoding, errors,
FileNotFoundError: [Errno 2] No such file or directory: '/home/training_data/ATR_page/Aurexus/aurexus_page_sem/entities.yml'