Remove PDF.js display hint

[bseeger]

We should evaluate whether or not we should remove the PDF.js option from Islandora Display Hints. It doesn't appear to be needed anymore and if selected actually degrades the user experience.

When a News Letter had PDF.js selected for a display hint, there ended up being two viewers rendered on the page. The 2nd viewer was unable to load the pdf. Also all the metadata displayed was from the media and none from the repository item itself.

When the metadata for the repository item was changed so the Display Hint was no longer set, the page rendered fine (with one viewer) and the appropriate metadata.

HOWEVER, Jared noticed that when we did that, the PDF.js no longer displays the PDF on the media's view page.

Perhaps it is better to fix this page like @jaredgalanis did with the Audio/Video pages.

UPDATE 11/16/2021: after Jared reviewed the behavior the pdf viewer never displays on the media page regardless of whether a display hint is enabled or not. Given this is not a consideration, Jared's current recommendation is to remove the display hint for pdfjs from the taxonomies, but that that shouldn't be a launch blocker because we can just not use the display hint in the meantime.

UPDATE 11/20/2021: after discussion @htpvu and @jaredgalanis agreed that no short-term fix is necessary because the system functions as expected if the display hint is not used and we've updated folks to not use it when making migrations and the test instance contains no usage of the display hint. The new work for this ticket is to remove the pdf.js display hint as a long-term fix. This will involve making a data change that will probably require a new snapshot.

[bseeger]

Ideal: is to render this PDF.js option to make its actions neutral. We could also suppress it from the form.

[htpvu]

@bseeger is this ticket still relevant?

[bseeger]

Hi @htpvu - Yes, but not vital to have fixed for launch.

[htpvu]

chatted with Jared&John. Jared will investigate.

[htpvu]

i'm going to move this ticket out of the initial launch project, as we focus our effort toward launch.