usage.rb: Add Report column showing consent forms signed by each student
usage.rb: Add Report column showing consent forms signed by each student

(Previous commit was for details report only… )
[#60714100]
https://www.pivotaltracker.com/story/show/60714100

concord-consortium/rigse,concord-consortium/rigse,concord-consortium/rigse,concord-consortium/rigse,concord-consortium/rigse,concord-consortium/rigse