Inspired by http://fluttericon.com/

We should be able to tree-shake our .ttf file that holds our material icons. Un-shaken, it's ~130K in size, but every icon takes up only ~300 bytes. We know from the app's usage of Icons what icons it actually needs, so we should be able to ship a font file that's much lower than 130K - likely saving over 100K on final app bundle size.