This PR contains the work done to implement the *User Wantlist* endpoints of the *Discogs API* online service in the `Open API` specification document:
* GET `/users/{username}/wants`
* POST `/users/{username}/wants/{release_id}`
* PUT `/users/{username}/wants/{release_id}`
* DELETE `/users/{username}/wants/{release_id}`
Reviewed-on: #13
Co-authored-by: Javier Cicchelli <javier@rock-n-code.com>
Co-committed-by: Javier Cicchelli <javier@rock-n-code.com>
javier