add pinned room events hook

src/app/hooks/useRoomPinnedEvents.ts

@@ -0,0 +1,15 @@
+import { useMemo } from 'react';
+import { RoomPinnedEventsEventContent } from 'matrix-js-sdk/lib/types';
+import { Room } from 'matrix-js-sdk';
+import { StateEvent } from '../../types/matrix/room';
+import { useStateEvent } from './useStateEvent';
+
+export const useRoomPinnedEvents = (room: Room): string[] => {
+  const pinEvent = useStateEvent(room, StateEvent.RoomPinnedEvents);
+  const events = useMemo(() => {
+    const content = pinEvent?.getContent<RoomPinnedEventsEventContent>();
+    return content?.pinned ?? [];
+  }, [pinEvent]);
+
+  return events;
+};