Merge pull request #19497 from OrestChura:oc/kmeans_ptest

[G-API]: Performance tests for kmeans

* - Perf.Tests for kmeans(2D, 3D (Point2f/3f), ND (Mat))
 - New file for common parts of acc. and perf. tests for core kernels added
 - Some typos corrections

* Applying comments

modules/gapi/test/common/gapi_imgproc_tests_common.hpp

@@ -194,4 +194,4 @@ static void fitLineTestBody(const In& in, const cv::DistanceTypes distType,
 }
 } // namespace opencv_test
 
-#endif // OPENCV_GAPI_VIDEO_TESTS_COMMON_HPP
+#endif // OPENCV_GAPI_IMGPROC_TESTS_COMMON_HPP