AO3-7182 Hide restricted works from guests on prompts page

[luis-pabon-tf]

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Issue

https://otwarchive.atlassian.net/browse/AO3-7182

Purpose

Fixes a visibility bug on the meme prompt page.

Credit

Luis Pabon (they/he)

[sarken]

Hi, Luis -- it's great to see you again!

Thank you for working on this, and I'm sorry we didn't see your comment on the issue asking for clarification about the intended behavior. We'd like the existence of these restricted works completely hidden from guests, the same way we hide restricted works on, e.g., tag work pages.

What that means is:

1. If the only fills for a prompt are restricted, the "Fulfilled By" listbox should not be displayed.
2. If there are both public and restricted fills for a prompt, the "Fulfilled By" listbox should be present, but only list the public works.

If you could make that change, we'd appreciate it!