Question ID Management needs an overhaul

[clpetersonucf]

We're not strictly enforcing uniqueness of question IDs the way we probably should: for instance, importing questions doesn't scrub the existing question ID, and importing the same question multiple times is an easy way to cause collisions. We need to better strip/regenerate question and answer IDs in a number of places:

• JS: in engine/creatorcore, prior to being passed to the creator during question import
• PHP: when storing into question bank

We'll have to manage handling both existing question IDs and creation/handling of new question IDs.

Lastly, we should switch to using uuids in find_questions on the PHP side.

[FrenjaminBanklin]

Refer to ucfopen/Materia-Server-Client-Assets#37.

[clpetersonucf]

Resolved via #1189