feat(live): Fixes in main_view.html template to show correct messages when live session or history or courslet.
feat(live): Fixes in main_view.html template to show correct messages when live session or history or courslet.

cjlee112/socraticqs2,raccoongang/socraticqs2,cjlee112/socraticqs2,cjlee112/socraticqs2,raccoongang/socraticqs2,raccoongang/socraticqs2,cjlee112/socraticqs2,raccoongang/socraticqs2