[fix] Add DeformableDetrFeatureExtractor (#19140)

* Add DeformableDetrFeatureExtractor

* Fix post_process

* Fix name

* Add tests for feature extractor

* Fix doc tests

* Fix name

* Address comments

* Apply same fix to DETR and YOLOS as well

Co-authored-by: Niels Rogge <nielsrogge@Nielss-MacBook-Pro.local>

docs/source/en/model_doc/deformable_detr.mdx

@@ -33,6 +33,16 @@ alt="drawing" width="600"/>
 
 This model was contributed by [nielsr](https://huggingface.co/nielsr). The original code can be found [here](https://github.com/fundamentalvision/Deformable-DETR).
 
+## DeformableDetrFeatureExtractor
+
+[[autodoc]] DeformableDetrFeatureExtractor
+    - __call__
+    - pad_and_create_pixel_mask
+    - post_process
+    - post_process_segmentation
+    - post_process_panoptic
+
+
 ## DeformableDetrConfig
 
 [[autodoc]] DeformableDetrConfig