Adding custom thumbnails to Works

[jlhardes]

Descriptive summary

This issue is brought to you by @samvera/hyrax-metadataists: Right now Hyrax limits thumbnail/representative image to files associated with a Work but there are cases where no file exists or files on Work cannot be used and current default icon is insufficient.

Acceptance Criteria/Expected Behavior

• Option to upload separate thumbnail stream (without taking away existing options)
• Bulkrax, Add new work, Add batch works, Edit work all include thumbnail option

Rationale (for feature request only)

Use cases:

• Metadata only records with custom thumbnails: Provide access (via URL) to a publisher copy of a book or article that the library is barred from adding to their IR. The publisher may have restrictive rights, and/or the faculty member might be uncomfortable providing anything but the published version.

• Metadata only records with custom thumbnails: Some faculty keep their websites and prefer a single access point from there. I don't know if this is a significant number at this point, though. It used to be more prevalent than it probably is now.

• Rights issues: Provide a custom logo, e.g. lock symbol, for restricted content as a reminder that works require authentication for access. Currently, public records with all restricted files appear defective. This is confusing for users. (Work is Public but Files are Private)

• Sensitivity issues - block specific content