move shell to separate thread

src/EventUtils.hh

@@ -0,0 +1,8 @@
+#pragma once
+
+#include <event2/event.h>
+
+#include <functional>
+#include <memory>
+
+void forward_to_event_thread(std::shared_ptr<struct event_base> base, std::function<void()>&& fn);