Remove unimplemented grade_summary feature.
Merge pull request #5290 from mitocw/bdero/fix-grade-summary-opaque-keys

Remove unimplemented legacy dashboard grade_summary feature
Converted annotation lettuce test into bok-choy test.
TNL-353
Merge pull request #5404 from edx/waheed/tnl353-wrote-annotation-bok-choy-test

Converted annotation lettuce test into bok-choy test.
Pinned thread should come first when sorting

Pinned threads come on the top when we sort threads
by most recent activities but in the most activities
and most vote case it doesn't come on top. Pinned
thread should come on top in any case of sorting

TNL-90