Randomise previewed quiz/test choices

[mlt47]

This branch adds a method which prepares questions in a test/quiz to be previewed. It is a subset of the tasks that are needed to augmentQuestionsForUser(...). Currently the only task is to randomise choices in Choice questions but, if there are future features that make use of it (such as initialising parametric questions), we should pull out the common code at that point into a separate private method.

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Pull Request Check List

• Unit Tests & Regression Tests Added (Optional)
• Removed Unnecessary Logs/System.Outs/Comments/TODOs
• Added enough Logging to monitor expected behaviour change
• Security - Data Exposure - PII is not stored or sent unencrypted
• Security - Data Exposure - Test any altered or created endpoints using swagger
• Updated Release Procedure & Documentation (& Considered Implications to Previous Versions)
• Peer-Reviewed

[codecov]

Codecov Report

Patch coverage: 100.00% and project coverage change: +0.05% 🎉

Comparison is base (e820e6f) 27.92% compared to head (bd65b2a) 27.98%.

Additional details and impacted files

@@            Coverage Diff             @@
##           master     #558      +/-   ##
==========================================
+ Coverage   27.92%   27.98%   +0.05%     
==========================================
  Files         504      504              
  Lines       22951    22955       +4     
  Branches     2843     2843              
==========================================
+ Hits         6410     6424      +14     
+ Misses      15929    15914      -15     
- Partials      612      617       +5     

Files Changed	Coverage Δ
...in/java/uk/ac/cam/cl/dtg/isaac/api/QuizFacade.java	43.98% <100.00%> (+0.07%)	⬆️
...cl/dtg/isaac/api/managers/QuizQuestionManager.java	83.33% <100.00%> (+0.38%)	⬆️

... and 3 files with indirect coverage changes

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