samples: gpu: removed inclusion of non-existent opencv2/contrib/contrib.hpp header, re-introduced TickMeter class in a separate header

This patch removes inclusion of opencv2/contrib/contrib.hpp header,
which does not exist anymore due to removal of opencv_contrib module.

The samples including this header appear to be doing so in order to
use TickMeter class; therefore, the latter is now provided by tick_meter.hpp
header file, located in samples/gpu folder.

samples/gpu/video_writer.cpp

@@ -10,7 +10,6 @@
 #include "opencv2/core.hpp"
 #include "opencv2/cudacodec.hpp"
 #include "opencv2/highgui.hpp"
-#include "opencv2/contrib.hpp"
 
 int main(int argc, const char* argv[])
 {