Individual Assignment submission tracking

[blipblitz]

A user requested some features we've discussed before, and it would be neat to include them at some point.

• The ability to see how many submissions an individual has made to a particular Assignment and Assignments in general. This would live on their profile page, I imagine. We may also want to put a link to Assignments from user pages for people in general, so people see it and know they have contributed to any. We may also want to consider changing the name to something suggesting "Shared tasks" or "Communal efforts".

• "In line with that also being able to see how I am doing compared to others working on the same assignment." This would take thinking through the gamification a bit, and I don't think this is a productive feature for all Assignments.