onnx importer backend pad reshape transpose

[pecanjk]

based on my yolov3_tiny onnx model file test. we find nnx importer backend pad ops reshape should transpose to match the dims

[sousoux]

The transpose patch is incorrect. You should use the -T option to the dump command.
The pad patch I guess is indicating that the second input is optional and should default to 0 but the patch is not doing that.