Enable Globus download from endpoints other than PDC

[matthewjchandler]

Notes

Following up from #80, we have a post-MVP request to enable some Globus integration with endpoints that we do not directly manage as part of PDC infrastructure. The specific use-case that raised this issue is GFDL, with whom we have an MOU to publish datasets in PDC which are hosted on their infrastructure. Here's an example: https://doi.org/10.34770/hbaw-c480. What Discovery shows is the metadata and the README, and the "Download from Globus" button only applies to the README file, since that is all we have in the PDC infrastructure. The actual dataset is available at https://app.globus.org/file-manager?origin_id=5ac03700-685a-4845-ab82-4a5771b58426&origin_path=%2F1%2Fusers%2FColleen.McHugh%2Fheat-extremes-data%2F, but we do not currently have a smooth way to direct anyone to that endpoint.

I expect this ticket will need some refinement still to get clear on the stakeholder needs and completion criteria.