Test cv::cuda::event

[cudawarped]

Add tests to cv::cuda::event. Some of these tests depend on opencv/opencv#21374 because they create events using combinations of flags.

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 other license that is incompatible with OpenCV
• The PR is proposed to proper branch
• There is reference to 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

opencv=fix_cuda_event_flags
force_builders=Custom
buildworker:Custom=linux-4,linux-6
Xbuild_image:Custom=ubuntu-cuda:18.04
build_image:Custom=ubuntu-cuda-cc52:18.04

[alalek]

Please take a look on these new warnigs:

/build/precommit-contrib_custom_linux64/4.x/opencv_contrib/modules/cudaarithm/test/test_event.cpp:116:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
/build/precommit-contrib_custom_linux64/4.x/opencv_contrib/modules/cudaarithm/test/test_event.cpp:127:16: warning: unused variable 'elTimeMs' [-Wunused-variable]

[alalek]

Please use short license header: https://github.com/opencv/opencv/wiki/Coding_Style_Guide#file-structure

// This file is part of OpenCV project.
// It is subject to the license terms in the LICENSE file found in the top-level directory
// of this distribution and at http://opencv.org/license.html.

[alalek]

Thank you 👍