Refresh user object in frontend

[rhaamo]

After uploading or deleting tracks, the user object isn't refreshed, the quota won't change or track count, something needs to be done on that side.

Two things can be done:

• Anything changing the content of a Track or User in the backend should returns a Track and/or User, that way it is going to be updated in the frontend (apiService might needs some edit)

• Using the notifications timelime to push new User on it that would be updated, we don't have that timeline implemented in the backend however.

The latter needs to have a notification read implemented to avoid the timeline returning all objects every time.