Fix stream render with menu bar

src/single_window/main_window.cpp

@@ -0,0 +1,16 @@
+#include "render.h"
+
+int Render::MainWindow() {
+  ImGui::SetNextWindowPos(ImVec2(0, 0), ImGuiCond_Always);
+  ImGui::SetNextWindowSize(ImVec2(main_window_width_, main_window_height_),
+                           ImGuiCond_Always);
+  ImGui::Begin("Render", nullptr,
+               ImGuiWindowFlags_NoMove | ImGuiWindowFlags_NoTitleBar |
+                   ImGuiWindowFlags_NoResize | ImGuiWindowFlags_NoScrollbar);
+  LocalWindow();
+  RemoteWindow();
+
+  ImGui::End();
+
+  return 0;
+}