Requires: mvdbeek/tusfilter#1

Adds CORS handling to TUS uploads.

TODO: Consider adding separate config setting for uploads allowed_upload_origin_hostnames, that could be made looser than other settings (e.g. '*'), with fall back to allowed_origin_hostnames, so that other Browser-based applications are able to upload datasets.

Example application is GiN (Galaxy in Notebooks), which can upload datasets from a User's computer to Galaxy via JS in a Jupyter Notebook: data is sent from user's computer directly to Galaxy, using credentials provided to GiN. Otherwise, datasets would need to be transferred from User's computer to Jupyter server, then sent e.g. via python/CURL/etc, to the Galaxy server, in order to get around CORS.

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