paginatedresource: allow for no content

[AndyTWF]

Handles the situation whereby an endpoint returns 204 that caused paginatedresource to throw an error. This does not check for the body actually being empty, but at least handles the situation whereby the response is obviously trying not to return one.

This does not fully address #676 in that it does not check the body itself for being empty and is not robust in this sense. However it at least respects the 204 status code - which will unblock other teams using the SDK.