Add an on-demand regenerate derivates option for FileSets [placeholder]

[eporter23]

This request is for repository admins to be able to regenerate derivatives for a given FileSet, which is similar to what we have in place for Curate.

This ticket may involve both front-end and back-end work to adjust the current page layout.

Acceptance criteria:

• An admin-level user should be able to navigate to the View FileSet page
• An admin-level user should see either a link or a button that offers an option to "Regenerate Derivatives"
• Clicking on this link should start the appropriate Hyrax job - in Curate, this runs as a job which can be seen in sidekiq