TUS support is broken

[ewohnlich]

Full disclosure, I don't know much about TUS. While researching it and Plone's support I found what appears to be bug.

https://github.com/plone/plone.app.content/blob/master/plone/app/content/browser/file.py#L41 this section checks if the python tus module is installed. I get an error here even though it is installed, because of a different error with tus.

Traceback (most recent call last):
  File "C:\Program Files\JetBrains\PyCharm 2023.2\plugins\python\helpers\pydev\pydevconsole.py", line 364, in runcode
    coro = func()
  File "<input>", line 1, in <module>
  File "C:\Program Files\JetBrains\PyCharm 2023.2\plugins\python\helpers\pydev\_pydev_bundle\pydev_import_hook.py", line 21, in do_import
    module = self._system_import(name, *args, **kwargs)
  File "C:\Users\oolit\PycharmProjects\plone\venv\lib\site-packages\tus\__init__.py", line 4, in <module>
    from StringIO import StringIO
  File "C:\Program Files\JetBrains\PyCharm 2023.2\plugins\python\helpers\pydev\_pydev_bundle\pydev_import_hook.py", line 21, in do_import
    module = self._system_import(name, *args, **kwargs)
ModuleNotFoundError: No module named 'StringIO'

This clearly hasn't been updated to python 3, and it's no surprise because the package hasn't been updated in 10 years. Perhaps support should be dropped, but if not it could use a test. I do not have the experience to help there :(

Original issue https://community.plone.org/t/large-chunked-uploads-and-maybe-tus-support-6-classic/17744/2