Changes to List clients

added the new optional query request parameter page[cursor]

added the new optional query request parameter page[size]

added the non-success response with the status 400

added the non-success response with the status 406

added the non-success response with the status 422

added the optional property included to the response with the 200 status

added the optional property links to the response with the 200 status

added the optional property meta to the response with the 200 status

added the required property data to the response with the 200 status

media type application/json was changed to a more specific media type application/vnd.api+json for the response status 200

media type application/json was changed to a more specific media type application/vnd.api+json for the response status 401

media type application/json was changed to a more specific media type application/vnd.api+json for the response status 403