Add details to sprite tile and update styling

src/components/asset-panel/icon--sound.svg

src/components/asset-panel/selector.jsx

src/components/sprite-selector-item/sprite-selector-item.css

src/components/sprite-selector-item/sprite-selector-item.jsx

src/containers/costume-tab.jsx

src/containers/sound-tab.jsx

...mponents/__snapshots__/sprite-selector-item.test.jsx.snap

test/unit/components/sprite-selector-item.test.jsx