Click handlers were not getting attached to DOM elements in some cases on slow running machines.
Added logic to attach handlers when elements are ready.
Added 2 buttons on metrics tab:
Download Subsection Data for downloading to csv.
Download Problem Data for downloading to csv.
Clicking on any of the bars displays a list of students for that
particular action (either opened the subsection or attempted the
problem).
Students are listed for the sub-sections.
Students, grade and percent are listed for the problems.
The on-screen list displays only the first 250 students with
an overflow message if there are more students than that.
The csv download lists all students.
Metrics tab shows student data:
-Count of students opened a subsection
-Grade distribution per problem
for each section/subsection of the course.
Implemented for both the old and beta dashboard
Controlled by a feature flag 'CLASS_DASHBOARD'
Data is aggregated across all students
Aggregate data computed from courseware_studentmodule
