[Router] : Friend Feature

[Celesca]

-- Friend Feature --
Story 8:
As a users, I want to see the friend request.

Technical Requirements:
REST API Endpoint: GET /friend_request/{user_id}
Path Variable: {user_id}
Response: 200 OK with the lists of friend request of that users!
Story 9:
As a users, I want to reject or approved the friend request.

Technical Requirements:
REST API Endpoint: POST /friend_request/approve/{user_id}
Path Variable: {user_id} are the people who will accepted or rejected.
Request Body: { "status": 1, "target_id": "XXX-XXX-XXXX" }
When the status 1 is approved and status 0 is rejected
Response: 200 OK when success and 400 Error when Request body isn't true.