message: fix(stream-responses): Don't modify body stream regardless of content type
diff: import { HttpHeaders } from '../http.interface';
  -import { ContentType } from '../+internal';
  +import { ContentType, isStream } from '../+internal';
  export const bodyFactory = (headers: HttpHeaders) => (body: any) => {
  + if(isStream(body)){
  + return body;
  + }
  switch (headers['Content-Type']) {
  case ContentType.APPLICATION_JSON:
  return JSON.stringify(body);
  