Typo fix: KadewTraKuPong to KaewTraKulPong

[Sarrink]

From his paper: https://scispace.com/pdf/an-improved-adaptive-background-mixture-model-for-real-time-1l517cez5l.pdf

Pull Request Readiness Checklist

See details at https://github.com/opencv/opencv/wiki/How_to_contribute#making-a-good-pull-request

• I agree to contribute to the project under Apache 2 License.
• To the best of my knowledge, the proposed patch is not based on a code under GPL or another license that is incompatible with OpenCV
• The PR is proposed to the proper branch
• There is a reference to the original bug report and related work
• There is accuracy test, performance test and test data in opencv_extra repository, if applicable
  Patch to opencv_extra has the same branch name.
• The feature is well documented and sample code can be built with the project CMake

[asmorkalov]

URL is broken: 403 ERROR The request could not be satisfied.

[sturkmen72]

https://www.researchgate.net/publication/2557021_An_Improved_Adaptive_Background_Mixture_Model_for_Realtime_Tracking_with_Shadow_Detection

[sturkmen72]

the paper "An Improved Adaptive Background Mixture Model for Realtime Tracking with Shadow
Detection" by P. KaewTraKulPong and R. Bowden in 2002. It uses a method to model each background

[sturkmen72]

it will be great if you edit other files accordingly https://github.com/search?q=repo%3Aopencv%2Fopencv_contrib%20Bowden&type=code

[Sarrink]

It is already spelled correctly in other files