Call this method to retrieve access to the HTTP response body data.
The response body contains the data retrieved as a result of the previous call to Navigate but does not include header information. This data is not processed in any way by CAtlHttpClientT. No parsing is performed for HTML or script data, and binary data is returned in raw form as retrieved from the server.
The size of the response body can be retrieved with CAtlHttpClientT::GetBodyLength.