Allow passing a list of fields when retrieving data

[roncli]

Title: Allow passing a list of fields when retrieving data

Issue found of: 10/13/2021

Endpoint(s):

• Any endpoint that returns data

Expected behaviour:

As an example, with the /users/{id}/tracks endpoint, it is currently returning a whole bunch of fields that I do not need for my application. It would be nice to have an optional fields querystring parameter, something along the lines of /users/{id}/tracks?fields=id,title,uri,permalink,user[username],... to get only the fields that are needed in the result. This could help greatly reduce request size.

Actual behaviour:

Currently, we get all of the data, even if we don't need all of it.