Remote webpack stats

[alexseitsinger]

Hello,

This makes _load_assets attempt to load the STATS_FILE over HTTP if it is a URL, otherwise it loads it from a file path as usual.

Best,
Alex

[tony]

This (in general) is a good idea and makes sense depending on the static file deployment pipeline being used.

[owais]

Dynamic loader classes have been implemented in master and I think we can rely on that for this feature. We could still ship a different remote loading class by default if someone wanted to contribute that.