Merge pull request #25075 from mshabunin:cleanup-imgproc-1

C-API cleanup: apps, imgproc_c and some constants #25075

Merge with https://github.com/opencv/opencv_contrib/pull/3642

* Removed obsolete apps - traincascade and createsamples (please use older OpenCV versions if you need them). These apps relied heavily on C-API
* removed all mentions of imgproc C-API headers (imgproc_c.h, types_c.h) - they were empty, included core C-API headers
* replaced usage of several C constants with C++ ones (error codes, norm modes, RNG modes, PCA modes, ...) - most part of this PR (split into two parts - all modules and calib+3d - for easier backporting)
* removed imgproc C-API headers (as separate commit, so that other changes could be backported to 4.x)

Most of these changes can be backported to 4.x.

modules/core/include/opencv2/core/private.hpp

@@ -134,13 +134,6 @@ static inline int cvAlign( int size, int align )
     return (size + align - 1) & -align;
 }
 
-#ifdef IPL_DEPTH_8U
-static inline cv::Size cvGetMatSize( const CvMat* mat )
-{
-    return cv::Size(mat->cols, mat->rows);
-}
-#endif
-
 namespace cv
 {
 CV_EXPORTS void scalarToRawData(const cv::Scalar& s, void* buf, int type, int unroll_to = 0);