Optimize naive Conv4D with flat contiguous buffers #4142

Job	Run time
build-linux-arm64	3m 5s
build-windows	7m 10s
build-linux-clang	6m 59s
clang-format	16s
codecov	12m 49s
build-macos	3m 43s
build-linux (RELEASE, false)	6m 9s
download-dataset	1m 41s
build-linux (DEBUG)	5m 56s
build-linux (RELEASE, true)	6m 9s
evaluate-model-alexnet	3m 32s
evaluate-models-onnx (googlenet)	13m 1s
evaluate-models-onnx (densenet)	23m 59s
evaluate-models-onnx (yolo)	29m 44s
evaluate-models-onnx (resnet)	3h 8m 38s
	5h 12m 51s

Provide feedback