DiffusionDet: Diffusion models for object detection

### Model/Pipeline/Scheduler description

Recent work which leverages diffusion models for object detection task. https://arxiv.org/abs/2211.09788

Add capability to run it through HF diffusers pipeline and if possible also create benchmarks or comparison on datasets like nuScenes.

### Open source status

- [X] The model implementation is available
- [ ] The model weights are available (Only relevant if addition is not a scheduler).

### Provide useful links for the implementation

_No response_