[Refactor][OutputProcessor 2/8]: OmniRequestOutput should inherit RequestOutput and no nested wrap-up (#5146)

Signed-off-by: Boao Shi <aoibosh@connect.hku.hk>
Signed-off-by: bowieshi <aoibosh@connect.hku.hk>
Signed-off-by: princepride <wangzhipeng628@gmail.com>
Signed-off-by: R2-Y <ruiruyang2@gmail.com>
Signed-off-by: amy-why-3459 <wuhaiyan17@huawei.com>
Signed-off-by: Shi Boao Bowie <aoibosh@connect.hku.hk>
Co-authored-by: 汪志鹏 <wangzhipeng628@gmail.com>
Co-authored-by: ruirui(rein) yang <73573651+R2-Y@users.noreply.github.com>
Co-authored-by: amy-why-3459 <wuhaiyan17@huawei.com>
Co-authored-by: Gao Han <hgaoaf@connect.ust.hk>
Co-authored-by: Hongsheng Liu <liuhongsheng4@huawei.com>

tests/e2e/accuracy/test_videogen_modelopt_quant.py

@@ -141,8 +141,8 @@ def _extract_frames(result) -> list[Image.Image]:
 
     if isinstance(result, list):
         result = result[0] if result else None
-    if isinstance(result, OmniRequestOutput) and result.is_pipeline_output and result.request_output is not None:
-        result = result.request_output
+    if isinstance(result, OmniRequestOutput) and result.is_pipeline_output and result is not None:
+        result = result
     images = getattr(result, "images", None)
     if not images:
         raise AssertionError("Pipeline output had no images")