API request: Course JSON with participants and their exercise status

There's a need for better API in TMC Server for resolving which students have been in a specific course and what is their exercise status. Now to get students of a specific course from TMC you need to navigate to

/:instanceId/courses/:courseId/points.json

and get student IDs from "users" attribute.

On the other hand, you can get exercise status from

/:instanceId/courses/:courseId/exercise_status/:studentId.json

Finally, for complete student information you need to get them from

/:instanceId/participants.json.

To solve all of this with just one request, we suggest the following path:

/:instanceId/courses/:courseId/participants.json

which returns something like this:

{ "id": "courseId", "participants": 
   [
      { "id": "1", "username": "name", "first_name": "first", "last_name": "last",
         "exercise_status": [
            { "exercise1": "status" }, { "exercise2": "status" }
         ]
      }
   ]
} 

This way we can easily find out which students are in the course, their information and which exercises they have been working on.

Start by reading the existing /:instanceId/courses/:courseId/points.json, exercise_status/:studentId.json, and /:instanceId/participants.json API entry points. Trace how each supplies course participants, student information, and exercise status. Done means /:instanceId/courses/:courseId/participants.json returns the course id and each participant with the proposed information and exercise-status fields in one response.