Implement antialiasing support in Resize operator

[robertknight]

The Resize operator doesn't currently support antialiasing (via the antialias attribute). This has been OK so far because the models I've been testing with haven't required it, as they mostly use Resize for upscaling. However when this operator is used for pre-processing model inputs, which is more likely to involve downsampling, the lack of antialiasing can lead to much worse output. This can hurt prediction accuracy if the model inputs were downsamples with antialiasing during training. See 958177f.