FRML-119 Make Standard Scaler fit on segments only

[Eve-ning]

Major Changes

• Make Standard Scaler fit on the train segments only instead of the whole image, which produces a more accurate range
• Improve formatting of logged variable names. Use <category>/<varname> to better format in WandB
• Expose the option to use implicit static ImageNet Scaling in model
• Unfreeze InceptionV3

Minor Changes

• Remove unused val_iters args