Remove unused svg files

src/vs/workbench/parts/explorers/browser/media/files-dark.svg

-<svg xmlns="http://www.w3.org/2000/svg" width="32" height="32"><path d="M17.705 8h-8.705s-2 .078-2 2v15s0 2 2 2l11-.004c2 .004 2-1.996 2-1.996v-11.491l-4.295-5.509zm-1.705 2v5h4v10h-11v-15h7zm5.509-6h-8.493s-2.016.016-2.031 2h8.015v.454l3.931 4.546h1.069v12c2 0 2-1.995 2-1.995v-11.357l-4.491-5.648z" fill="#fff"/></svg>
\ No newline at end of file