Mentors can see student ratings for each topic

**As a** mentor
**I want** to see the topic ratings of students in my course
**So that** I can understand which students need more help with a topic.

## Acceptance Criteria
When I login as a mentor...
- [x] ...and visit `/lesson/:lessonId`, I can see all of the topics in that lesson.
- [x] ... and visit the list of topics in a lesson, I can see the ratings that each student has given each topic.
- [x] ...and see the list of lessons in the dashboard (#134), I can click on a lesson to view the topics in that lesson.
- [x] ...and visit the list of topics in a lesson, I can go back to my dashboard.