From Carson requests

[tclzcja]

• [x] By default, Gradebook should select the 1st assigned Group of the Quiz, if there's any.
• [x] A new option for question summary: do not show grades across the whole Gradebook. This is for only to show the question summary as a survey (so grade doesn't make sense in this case).
• [x] Find a way to hide all users in Gradebooks (maybe collide them like "un-answer users"), if the teacher only wants to know question analytics. (related to number 2).
• [x] Add a refresh button to Gradebook and/or Question Summary panel.

[tclzcja]

I think number 2 should be covered by number 3. Closing this. Confirm with Carson later.