Add Question Groups

[thomasplevy]

Question groups were started in 3.16 but were not finished and thus never released.

This issue outlines the proposed feature set for question groups.

• Question Groups can contain other questions (but not other question groups)
• Banking: Question groups will have the ability to pull a N questions from the questions in the group
  • When banking is enabled the quizz's total points becomes a variable range eg: 25 - 30 points
  • Upon initialization of a new quiz a random N questions will be added to the attempt
• Groups will contain options akin to a Content question and during a quiz the group itself will display like a content group (Show the title, desc, features, etc... and be worth 0 points)