Add license to interactive-calibration app sources

apps/interactive-calibration/main.cpp

@@ -1,8 +1,13 @@
+// This file is part of OpenCV project.
+// It is subject to the license terms in the LICENSE file found in the top-level directory
+// of this distribution and at http://opencv.org/license.html.
+
 #include <opencv2/core.hpp>
 #include <opencv2/calib3d.hpp>
 #include <opencv2/aruco/charuco.hpp>
 #include <opencv2/cvconfig.h>
 #include <opencv2/highgui.hpp>
+
 #include <string>
 #include <vector>
 #include <stdexcept>