added support of multichannel images into gpu::matchTemplate (all methods except CCOEFF based), refactored
added support of multichannel images into gpu::matchTemplate (all methods except CCOEFF based), refactored

opencv/opencv,opencv/opencv,opencv/opencv,apavlenko/opencv,apavlenko/opencv,opencv/opencv,opencv/opencv,opencv/opencv,apavlenko/opencv,apavlenko/opencv,opencv/opencv,opencv/opencv,apavlenko/opencv,apavlenko/opencv,opencv/opencv,opencv/opencv