remove ui namespace which is not really used, move CameraData in camera_modes.h to avoid the inclusion of canva.h

src/app_events.cpp

@@ -10,8 +10,6 @@ std::string win32_open_dir();
 #endif
 
 
-using namespace ui;
-
 void App::tick(float dt)
 {
     layout[main_id]->tick(dt);