[FancyZones] Responsive drawing (#7125)

* Made drawing zones not clog message processing

* Fixed synchronization bugs

* call BufferedPaintInit

* Some refactoring, the animation is back

* Rename a function

* Align parameters

src/common/on_thread_executor.cpp

@@ -16,6 +16,14 @@ std::future<void> OnThreadExecutor::submit(task_t task)
     return future;
 }
 
+void OnThreadExecutor::cancel()
+{
+    std::lock_guard lock{ _task_mutex };
+    _task_queue = {};
+    _task_cv.notify_one();
+}
+
+
 void OnThreadExecutor::worker_thread()
 {
     while (!_shutdown_request)

src/common/on_thread_executor.h

@@ -18,6 +18,7 @@ public:
     OnThreadExecutor();
     ~OnThreadExecutor();
     std::future<void> submit(task_t task);
+    void cancel();
 
 private:
     void worker_thread();