Add ONNX export support for DinoV2, Hiera, Maskformer, PVT, SigLIP, SwinV2, VitMAE, and VitMSN models (#2001)
* Add support for siglip models
* cleanup
* remove submodule
* Add ONNX export for DinoV2 models
* Use height and width from preprocessor
* formatting
* Remove attention mask from model input
* Add ONNX export support for Hiera models
* Add ONNX export support for SwinV2
* Upgrade Siglip to opset=14
* Add VQA task
* Add ONNX export support for Maskformer
* Add ONNX export support for PVT
* Add ONNX export support for ViTMAE and ViTMSN
* Add siglip unit tests
* Add vit-mae unit tests
* Code formatting
* Add maskformer to list of supported models
* Formatting
* fix typo
* remove vit-mae masked-im task
* remove vit-msn masked-im task
* fix output names for maskformer export
---------
Co-authored-by: Ella Charlaix <ella@huggingface.co>