Refactor the menubar and separate student, tutor and reviewer views

The menubar should separate different views and organise functionality. Well, because that is what a menubar does.

created branch 20-refactor-the-menubar-and-separate-student-tutor-and-reviewer-views

mentioned in merge request !2 (merged)

closed via commit bf831e86

closed via merge request !2 (merged)

mentioned in commit bf831e86