Refactor new editor host orchestration

new_editor/app/Host/WindowMessageDispatcher.h

@@ -0,0 +1,34 @@
+#pragma once
+
+#ifndef NOMINMAX
+#define NOMINMAX
+#endif
+
+#include <windows.h>
+
+namespace XCEngine::UI::Editor {
+class Application;
+}
+
+namespace XCEngine::UI::Editor::Host {
+
+class WindowMessageDispatcher {
+public:
+    static Application* GetApplicationFromWindow(HWND hwnd);
+    static bool TryHandleNonClientCreate(
+        HWND hwnd,
+        UINT message,
+        LPARAM lParam,
+        LRESULT& outResult);
+    static bool TryDispatch(
+        Application& application,
+        UINT message,
+        WPARAM wParam,
+        LPARAM lParam,
+        LRESULT& outResult);
+
+private:
+    static void RequestDeferredRenderFrame(Application& application);
+};
+
+} // namespace XCEngine::UI::Editor::Host