Add `ChallengeSummary` to Swagger

The API endpoint https://maproulette.org/api/v2/data/challenge/38309?includeByPriority=false is not documented in the Swagger Docs at https://maproulette.org/docs/swagger-ui/index.html#/

I found some hints on how to authenticate in https://github.com/maproulette/maproulette-backend/blob/main/postman/maproulette2.postman_collection.json#L4776-L4811

It provides a response like

[
    {
        "id": 38309,
        "name": "Missing buildings - Scotland",
        "actions": {
            "total": 8608,
            "available": 4021,
            "fixed": 2941,
            "falsePositive": 266,
            "skipped": 30,
            "deleted": 0,
            "alreadyFixed": 1325,
            "tooHard": 25,
            "answered": 0,
            "validated": 0,
            "disabled": 0,
            "avgTimeSpent": -451551,
            "tasksWithTime": 4587
        }
    }
]

Another thing is, that IMO this API endpoint should not require an authentication. Other endpoints like the general challenge info do not require authentication. But unfortunately that only includes very basic data on the completion state.

Start with the /api/v2/data/challenge/{id} endpoint and the authentication hints in postman/maproulette2.postman_collection.json at lines 4776-4811. Compare the endpoint with the Swagger UI and its sample response. Done means ChallengeSummary and the endpoint response are represented in Swagger, with the authentication requirement clarified.