Split highgui module to videoio and highgui

doc/tutorials/introduction/windows_visual_studio_image_watch/windows_visual_studio_image_watch.rst

@@ -32,7 +32,7 @@ Image Watch works with any existing project that uses OpenCV image objects (for
 
     #include <iostream>                        // std::cout
     #include <opencv2/core/core.hpp>           // cv::Mat
-    #include <opencv2/highgui/highgui.hpp>     // cv::imread()
+    #include <opencv2/imgcodecs/imgcodecs.hpp>     // cv::imread()
     #include <opencv2/imgproc/imgproc.hpp>     // cv::Canny()
 
     using namespace std;