samples: avoid using of legacy C-like API

- CV_RGB() macro is moved into opencv2/imgproc.hpp from imgproc_c.h
- samples/cpp/filestorage_base64.cpp is dropped

modules/imgproc/include/opencv2/imgproc.hpp

@@ -4339,6 +4339,10 @@ CV_EXPORTS_W void applyColorMap(InputArray src, OutputArray dst, InputArray user
 //! @addtogroup imgproc_draw
 //! @{
 
+
+/** OpenCV color channel order is BGR[A] */
+#define CV_RGB(r, g, b)  cv::Scalar((b), (g), (r), 0)
+
 /** @brief Draws a line segment connecting two points.
 
 The function line draws the line segment between pt1 and pt2 points in the image. The line is

modules/imgproc/include/opencv2/imgproc/imgproc_c.h

@@ -982,7 +982,6 @@ CVAPI(void)  cvFitLine( const CvArr* points, int dist_type, double param,
 *       If a drawn figure is partially or completely outside of the image, it is clipped.*
 \****************************************************************************************/
 
-#define CV_RGB( r, g, b )  cvScalar( (b), (g), (r), 0 )
 #define CV_FILLED -1
 
 #define CV_AA 16