onnx-light — backend test coverage

Pass / fail status of every ONNX backend node test (the same tests exercised by xadupre/onnx-light's reference implementation) when executed against onnxruntime and the Python reference implementation shipped with onnx (onnx.reference.ReferenceEvaluator). Use the filter below to narrow the table to tests matching a regular expression — the pass ratio is recomputed for the selection.