Expose RAW Response object

NOTE: not really an issue

i want to preform the following using httpie

```
const file = fs.createWriteStream("file.jpg");
const request = http.get("https://somedomain.com/sampleimage.jpg", function(response) {
response.pipe(file);
});
```

whats the best way of doing so?

double note: im asking here as it might be a good example to have for other users

No file or test is named. Start by reading the existing response API and user examples to determine whether the underlying response object is already available; confirm how HTTPie handles response bodies and streaming. Done should be a clearly documented, supported way to access or stream the raw response, with an example if that is the agreed scope.

Written by the indexing model from the issue text.