Large response handling causes high memory usage (PDF generation use case)

### Large response handling causes high memory usage (PDF generation use case)

**Description**  
SDK loads entire response into memory, problematic for large files.

**Code snippet**

    response = client.request(
        "POST",
        base_url,
        "/pdf",
        data=payload
    )

    print(len(response))

**Issue**  
No streaming support (e.g. iter_content).