Pilot (Student Libraries): Require comments to publish libraries

[jmkulwik]

This requires comments on every exported library function.

For reference, this was the original PR that added comments: #28783

Spec for reference: https://docs.google.com/document/d/1jMLm_ghCshFen-h9vInAuXwEGXI-HPMjSP8dYeISfM0/edit?pli=1#

This code is largely experimental. If we go forward with Student Libraries, all code here will go through a second CR for production quality review. Review this PR to evaluate the following:

• Isolation: Will the reviewed code affect parts of the product that are not part of the pilot?
• Will the code fail in ways that will cause the pilot to be unsuccessful?
• Is there an obviously easier or better way to implement the piloted feature?

Although the piloting process is still under review, I am following the procedures in this doc: https://docs.google.com/document/d/10QvRAVOTEenFJa1wwrY0Twkd0anTDpkkzNeGnT_HH0o/edit

[joshlory]

Can you link to the previous PR that added the comment boxes?

[jmkulwik]

Can you link to the previous PR that added the comment boxes?

Sure! Added to the description. Also here: #28783