fix(rating): add props for accessible labels, structure as radio button (#1264)

* fix(rating): add props for accessible labels, structure as radio button

* update star styles for ratings component

Author: paulcpederson

src/components/calcite-rating/calcite-rating-resources.ts

@@ -0,0 +1,4 @@
+export const TEXT = {
+  rating: "Rating",
+  stars: "stars: ${num}"
+};