Canvas Quiz De-suckifier

NOTICE: "TAILOR MADE FOR REYKJAVÍK UNIVERSITY. MIGHT NOT WORK FOR PEOPLE OUTSIDE OF THE SCOPE UNLESS SOME CHANGES ARE MADE TO THE SOURCE CODE"

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This extension adds the clickable link "Populate with basic regex" besides the "Add another answer" link.
This is only intended for use with "Fill in the blank" and "Fill in multiple blanks" types of questions. The behaviour of this extension is undefined outside of this scope.

Basic syntax:
[abc]: any character a, b or c
--E is the empty character:
[abc--E]: any character a, b, c, or nothing/empty character.
--S is a flag that splits words on | inside the []
Example: [--SLorem|Ipsum|--E] is either Lorem, Ipsum or nothing/empty character.

{optional}: the string within {} becomes optional
Example: '{A }boat' yields both "A boat" and "boat"

$$variable$$:
To populate correctly for a variable in the
"Fill in multiple blanks" section, the regex query
MUST START with $$variable$$ as a selector for your intended variable.
Example: $$color1$$[--Syellow|blue|green]
populates the "color1" variable with yellow, blue and green.

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Version 0.1
Single fill in the blanks seem to work

Version 0.2
Multiple fill in the blanks work only when it is the first question

Version 0.3
Introduced $$variable$$ selection and a global limiter on variable names because of Canvas' global scope per input values (results in no more undefined behaviour for multiple questions per quiz)

Version 0.3.1
Added a matcher for question banks as well.