Merge pull request #25060 from dmatveev:dm/gapi_test_time

G-API: Make test execution lighter (first attempt) #25060

### Background

G-API tests look running longer than tests for the rest of modules (e.g., 5m), and the analysis show that there's several outliers in G-API test suite which take a lot of time but don't improve the testing quality much:
![image](https://github.com/opencv/opencv/assets/144187/e6df013f-e548-47ac-a418-285b3f78c9f8)

In this PR I will cut the execution time to something reasonable.

### Contents

- Marked some outliers as `verylong`:
  - OneVPL barrier test - pure brute force
  - Stateful test in stream - in fact BG Sub accuracy test clone
- Restructured parameters instantiation in Streaming tests to generate less test configurations (54 -> 36)

### Pull Request Readiness Checklist

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

- [x] I agree to contribute to the project under Apache 2 License.
- [x] 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
- [x] The PR is proposed to the proper branch
- [x] There is a reference to the original bug report and related work
- [x] There is accuracy test, performance test and test data in opencv_extra repository, if applicable
      Patch to opencv_extra has the same branch name.
- [x] The feature is well documented and sample code can be built with the project CMake

modules/gapi/test/streaming/gapi_streaming_utils_test.cpp

@@ -245,6 +245,7 @@ TEST(OneVPL_ElasticBarrier, single_thread_visit)
 
 TEST(OneVPL_ElasticBarrier, multi_thread_visit)
 {
+    applyTestTag(CV_TEST_TAG_VERYLONG);
     TestBarrier tested_barrier;
 
     static const size_t max_visit_count = 10000000;