[Feature Proposal] Better-optimized SVG encoding than URL-encoding and base64

I just came across this article which is relevant to Less w/ data-uri encoding: https://codepen.io/tigt/post/optimizing-svgs-in-data-uris

Basically, there was a discussion in the past about base64 vs. URL encoding for SVGs. (See: #2250 and #2184) There are a few additional optimizations in URL encoding that can make the encoding even smaller, as discovered by the research on that article. This is an improvement since URL-encoding by itself can inflate the output greater than base64 encoding.