New composition area with emoji typeahead

ts/components/stickers/lib.ts

@@ -0,0 +1,17 @@
+import { StickerPackType } from '../../state/ducks/stickers';
+
+// This function exists to force stickers to be counted consistently wherever
+// they are counted (TypeScript ensures that all data is named and provided)
+export function countStickers(o: {
+  knownPacks: ReadonlyArray<StickerPackType>;
+  blessedPacks: ReadonlyArray<StickerPackType>;
+  installedPacks: ReadonlyArray<StickerPackType>;
+  receivedPacks: ReadonlyArray<StickerPackType>;
+}) {
+  return (
+    o.knownPacks.length +
+    o.blessedPacks.length +
+    o.installedPacks.length +
+    o.receivedPacks.length
+  );
+}