User Detail endpoint (API)

[jack-michaud]

Keep #11 in mind.

Create a /user/<userId>/ endpoint that returns a User

interface BasicInfo {
  id: string;
  name: string;
  imageUrl: string;
}

interface User {
  id: string;
  name: string;
  imageUrl: string;
  // ISO timestamp
  joined: string;
  spotifyId: string;
  refreshToken: string
  accessToken: string
  playlists: BasicInfo[]
  favoriteTrack: BasicInfo[]
  favoriteArtists: BasicInfo[]
  favoriteAlbums: BasicInfo[]
  favoriteGenres: BasicInfo[]
}