Expiring links to S3 resources should be generated on click instead of page load

[rocketeerbkw]

There are a few places in the api/ui where Lagoon stores and retrieves files. Currently these are environment backups, task files and insights. The files are retrieved directly from S3 using a signed/short-lived link, meaning no Lagoon authorization is performed once a link is generated. The current system generates a link on page load valid for 5 minutes, in order to account for time that a user might be doing other tasks in between the page load and them clicking the link.

By moving the link generation from the page load to the moment they click the link, that would allow us to shorten the time a link is valid to reduce the risk of unauthorized access.