Display call member speaking status on bottom bar (#2742)

* add mutation observer hok

* add hook to read speaking member by observing iframe content

* display speaking member name in call status bar and improve layout

* fix shrining

src/app/hooks/useMutationObserver.ts

@@ -0,0 +1,37 @@
+import { useEffect, useMemo } from 'react';
+
+export type OnMutationCallback = (mutations: MutationRecord[]) => void;
+
+export const getMutationRecord = (
+  target: Node,
+  mutations: MutationRecord[]
+): MutationRecord | undefined => mutations.find((mutation) => mutation.target === target);
+
+export const useMutationObserver = (
+  onMutationCallback: OnMutationCallback,
+  observeElement?: Node | null | (() => Node | null),
+  options?: MutationObserverInit
+): MutationObserver => {
+  const mutationObserver = useMemo(
+    () => new MutationObserver(onMutationCallback),
+    [onMutationCallback]
+  );
+
+  useEffect(() => () => mutationObserver?.disconnect(), [mutationObserver]);
+
+  useEffect(() => {
+    const element = typeof observeElement === 'function' ? observeElement() : observeElement;
+
+    if (element) {
+      mutationObserver.observe(element, options);
+    }
+
+    return () => {
+      if (element) {
+        mutationObserver.disconnect();
+      }
+    };
+  }, [mutationObserver, observeElement, options]);
+
+  return mutationObserver;
+};