Move non-CV functionality from core.hpp to separate utility.hpp header

samples/cpp/tutorial_code/calib3d/camera_calibration/camera_calibration.cpp

@@ -3,10 +3,11 @@
 #include <time.h>
 #include <stdio.h>
 
-#include <opencv2/core/core.hpp>
-#include <opencv2/imgproc/imgproc.hpp>
-#include <opencv2/calib3d/calib3d.hpp>
-#include <opencv2/highgui/highgui.hpp>
+#include <opencv2/core.hpp>
+#include <opencv2/core/utility.hpp>
+#include <opencv2/imgproc.hpp>
+#include <opencv2/calib3d.hpp>
+#include <opencv2/highgui.hpp>
 
 using namespace cv;
 using namespace std;