Qt: Add new cheat manager

src/duckstation-qt/qthostinterface.h

@@ -167,6 +167,7 @@ public Q_SLOTS:
   void setCheatEnabled(quint32 index, bool enabled);
   void applyCheat(quint32 index);
   void reloadPostProcessingShaders();
+  void executeOnEmulationThread(std::function<void()> callback, bool wait = false);
 
 private Q_SLOTS:
   void doStopThread();
@@ -254,6 +255,7 @@ private:
   QThread* m_original_thread = nullptr;
   Thread* m_worker_thread = nullptr;
   QEventLoop* m_worker_thread_event_loop = nullptr;
+  Common::Event m_worker_thread_sync_execute_done;
 
   std::atomic_bool m_shutdown_flag{false};