[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>
