message: GAPI: GAPI_LOG_DEBUG facility
diff: # include "opencv2/core/utils/logger.hpp"
  # define GAPI_LOG_INFO(tag, ...) CV_LOG_INFO(tag, __VA_ARGS__)
  # define GAPI_LOG_WARNING(tag, ...) CV_LOG_WARNING(tag, __VA_ARGS__)
  +# define GAPI_LOG_DEBUG(tag, ...) CV_LOG_DEBUG(tag, __VA_ARGS__)
  #else
  # define GAPI_LOG_INFO(tag, ...)
  # define GAPI_LOG_WARNING(tag, ...)
  +# define GAPI_LOG_DEBUG(tag, ...)
  #endif // !defined(GAPI_STANDALONE)
  