IiifPrint Valkyrization issues

[jillpe]

Summary

• [ ] 'Re-split' button on a fileset does not work
• [x] is_child term not included on child works
• [x] custom iiif_print terms appeared on resource forms
• [ ] thoroughly test Rob's refactor so PR can be merged
• [ ] delete a work should delete all spawned child works

[Example](https://lkr.hyku-demo.notch8.cloud/concern/parent/7554a87b-40c2-42d5-aadb-24c4451a338a/file_sets/66c9cc6d-e304-443f-8b1e-a7a7db4f4f56) The 're-split pdf' button on a fileset show page does not kick off any jobs, thus does not resplit the fileset. See video below. https://github.com/scientist-softserv/hykuup_knapsack/assets/84697174/f68d3e0d-742c-4197-9d72-beafbda7edf8

Acceptance Criteria

All above issues are resolved.