Run node-svgo to crush all SVGs whilst retaining readibility

Done with:

svgo -f src/styles/images/*/ \
     --pretty \
     --disable=removeXMLProcInst \
     --disable=cleanupIDs \
     --disable=collapseGroups

Change-Id: I4de3284418b23ef8c9fd557b1ec7f4b573aaa470