add /api/v1/users/{user_id}/stats endpoint

[andreaskoepf]

Allow to query UserScores (all time frames) for a single user.

Result JSON:

{
  "day": {
    "rank": 1,
    "user_id": "38312e49-8cd6-4e7c-8bad-c626e452b1e7",
    "username": "__dummy_user__",
    "auth_method": "local",
    "display_name": "Dummy User",
    "leader_score": 312,
    "base_date": "2023-01-14T16:49:24.883512",
    "modified_date": "2023-01-15T16:49:24.883524",
    "prompts": 0,
    "replies_assistant": 0,
    "replies_prompter": 0,
    "labels_simple": 0,
    "labels_full": 0,
    "rankings_total": 0,
    "rankings_good": 0,
    "accepted_prompts": 0,
    "accepted_replies_assistant": 0,
    "accepted_replies_prompter": 0,
    "reply_ranked_1": 24,
    "reply_ranked_2": 24,
    "reply_ranked_3": 24,
    "streak_last_day_date": null,
    "streak_days": null
  },
  "week": {
   // ...
  },
  "month": {
   // ...
  },
  "total": {
   // ...
  }
}

[yk]

thank you!