add humanseg model and test data

[wjj19950828]

test data and onnx model for PR:opencv/opencv#20511

[fengyuentau]

Patch size is limited to 1024KiB. You can try follow this example to generate an ONNX model with the single layer you want to test.

[wjj19950828]

Because my model is exported from Paddle to ONNX,but generate_onnx_model.py use PyTorch,so can i upload the ONNX model to Google Drive like this:#773

[fengyuentau]

Because my model is exported from Paddle to ONNX,but generate_onnx_model.py use PyTorch,so can i upload the ONNX model to Google Drive like this:#773

1. Your regression test is for the Resize layer, so please push an ONNX for the test of this layer only. You can take a look at the script and other ONNX models, which all follow the same principle. Make an ONNX like this:

Input -> Resize -> Output

2. In cases like [GSoC] test data for scene text detection and recognition (High Level API) #773 , you can place the your GDrive URL in https://github.com/opencv/opencv_extra/blob/3.4/testdata/dnn/download_models.py like the following:
   

   opencv_extra/testdata/dnn/download_models.py

   Lines 842 to 846 in af56985

   	Model(
   	name='YOLOv4', # https://github.com/opencv/opencv/issues/17148
   	downloader=GDrive('1cewMfusmPjYWbrnuJRuKhPMwRe_b9PaT'),
   	sha='0143deb6c46fcc7f74dd35bf3c14edc3784e99ee',
   	filename='yolov4.weights'),

[wjj19950828]

Because my model is exported from Paddle to ONNX,but generate_onnx_model.py use PyTorch,so can i upload the ONNX model to Google Drive like this:#773

1. Your regression test is for the Resize layer, so please push an ONNX for the test of this layer only. You can take a look at the script and other ONNX models, which all follow the same principle. Make an ONNX like this:

Input -> Resize -> Output

1. In cases like [GSoC] test data for scene text detection and recognition (High Level API) #773 , you can place the your GDrive URL in https://github.com/opencv/opencv_extra/blob/3.4/testdata/dnn/download_models.py like the following:
   

   opencv_extra/testdata/dnn/download_models.py

   Lines 842 to 846 in af56985

   	Model(
   	name='YOLOv4', # https://github.com/opencv/opencv/issues/17148
   	downloader=GDrive('1cewMfusmPjYWbrnuJRuKhPMwRe_b9PaT'),
   	sha='0143deb6c46fcc7f74dd35bf3c14edc3784e99ee',
   	filename='yolov4.weights'),

Thanks for your suggestions~

[alalek]

Need to squash commits into one to reduce size of git history.

[wjj19950828]

Need to squash commits into one to reduce size of git history.

Thank you for your help~