feature request: reporting stage - allow students to login to view their feedback

[paulusm]

This addition would allow students to view anonymised comments and their overall score following a peer review round.

It might work as follows:

1. A review can be flagged as "active" or "closed" by the instructor
2. Once "closed", no new reviews can be added.
3. Students then use the same code to login, and can see anonymised, aggregated comments and their overall score. In the case that no reviews received, it would just say e.g. "Sorry, no peer reviews cwere received from your team"