Code-split emoji-mart picker and data (#5175)

app/javascript/mastodon/emoji_data_light.js

@@ -0,0 +1,17 @@
+// @preval
+const data = require('emoji-mart/dist/data').default;
+const pick = require('lodash/pick');
+
+const condensedEmojis = {};
+Object.keys(data.emojis).forEach(key => {
+  condensedEmojis[key] = pick(data.emojis[key], ['short_names', 'unified', 'search']);
+});
+
+// JSON.parse/stringify is to emulate what @preval is doing and avoid any
+// inconsistent behavior in dev mode
+module.exports = JSON.parse(JSON.stringify({
+  emojis: condensedEmojis,
+  skins: data.skins,
+  categories: data.categories,
+  short_names: data.short_names,
+}));