Optimize SVG images

[Niels-IO]

This would be a breaking change, as the Image component just passed SVG through.

This PR would optimize SVGs into images (webp or png) which could be smaller sometimes.

The unoptimized prop would yield the original SVG.

What is missing currently, is for remote images to create a src with a downloaded (and unoptimized) version of the svg and fall back to the remote source if the local image is not available.

[joshuabaker]

In my opinion, I don’t think it’s wise to make these lossy (i.e. webp or png). Instead, using SVGO with a minimal set of default adjustments (i.e. to avoid excessive path minification) would be better (as requested in #195).

[joshuabaker]

As noted in #184 (comment), just passing these through is likely the best starting point for SVG handling.