Merge pull request #28588 from abhishek-gola:ORT_GPU_wrapper

Added OnnxRuntime GPU wrapper #28588

### Pull Request Readiness Checklist

See details at https://github.com/opencv/opencv/wiki/How_to_contribute#making-a-good-pull-request

- [x] I agree to contribute to the project under Apache 2 License.
- [x] To the best of my knowledge, the proposed patch is not based on a code under GPL or another license that is incompatible with OpenCV
- [x] The PR is proposed to the proper branch
- [x] There is a reference to the original bug report and related work
- [x] There is accuracy test, performance test and test data in opencv_extra repository, if applicable
      Patch to opencv_extra has the same branch name.
- [x] The feature is well documented and sample code can be built with the project CMake

doc/tutorials/introduction/config_reference/config_reference.markdown

@@ -526,6 +526,7 @@ OpenCV have own DNN inference module which have own build-in engine, but can als
 | `WITH_OPENVINO` | _OFF_ | Enable Intel OpenVINO Toolkit support. Should be used for OpenVINO>=2022.1 instead of `WITH_INF_ENGINE` and `WITH_NGRAPH`. |
 | `WITH_ONNXRUNTIME` | _OFF_ | Enable Microsoft ONNX Runtime backend support for OpenCV DNN. |
 | `DOWNLOAD_ONNXRUNTIME` | _OFF_ | Download official ONNX Runtime prebuilt binaries when enabled (or when ONNX Runtime is not available in system paths). |
+| `DOWNLOAD_ONNXRUNTIME_GPU` | _OFF_ | Download GPU-enabled ONNX Runtime prebuilt binaries when available (Windows x64 and Linux x64 only). Requires `WITH_ONNXRUNTIME=ON`. |
 | `ONNXRUNTIME_PREFER_STATIC` | _ON_ | Prefer static `libonnxruntime.a` when both static and shared ONNX Runtime libraries are available. |
 | `ONNXRUNTIME_VERSION` | _1.24.2_ | ONNX Runtime version to download for prebuilt packages. |
 | `OPENCV_DNN_CUDA` | _OFF_ | Enable CUDA backend. [CUDA](https://en.wikipedia.org/wiki/CUDA), CUBLAS and [CUDNN](https://developer.nvidia.com/cudnn) must be installed. |