Add recently used section to emoji board (#373)

* Add recent section to emoji board

* Add section to emoji board sidebar

* Add emoji limit like element web has

* Ignore custom emojis

* Filter out invalid emojis

* Update heart icon with clock

Co-authored-by: Krishan <33421343+kfiven@users.noreply.github.com>

src/app/organisms/emoji-board/recent.js

@@ -0,0 +1,36 @@
+import initMatrix from '../../../client/initMatrix';
+import { emojis } from './emoji';
+
+const eventType = 'io.element.recent_emoji';
+
+function getRecentEmojisRaw() {
+  return initMatrix.matrixClient.getAccountData(eventType).getContent().recent_emoji ?? [];
+}
+
+export function getRecentEmojis(limit) {
+  const res = [];
+  getRecentEmojisRaw()
+    .sort((a, b) => b[1] - a[1])
+    .find(([unicode]) => {
+      const emoji = emojis.find((e) => e.unicode === unicode);
+      if (emoji) return res.push(emoji) >= limit;
+      return false;
+    });
+  return res;
+}
+
+export function addRecentEmoji(unicode) {
+  const recent = getRecentEmojisRaw();
+  const i = recent.findIndex(([u]) => u === unicode);
+  let entry;
+  if (i < 0) {
+    entry = [unicode, 1];
+  } else {
+    [entry] = recent.splice(i, 1);
+    entry[1] += 1;
+  }
+  recent.unshift(entry);
+  initMatrix.matrixClient.setAccountData(eventType, {
+    recent_emoji: recent.slice(0, 100),
+  });
+}