JS bindings for MSER are broken in 5.x

[asmorkalov]

System Information

MSER test fails:

 Fix test failure Expected: 7 Result: 0

Code:

Detailed description

Steps to reproduce

Code:

opencv/modules/js/test/test_features2d.js

Line 31 in 53f5127

let mser = new cv.MSER();

docker: quay.io/opencv-ci/opencv-docs-js-20.04:20240219
build command: emcmake python ../opencv/platforms/js/build_js.py js --build_test
test in browser: firefox ./bin/tests.html

Issue submission checklist

• I report the issue, it's not a question
• I checked the problem with documentation, FAQ, open issues, forum.opencv.org, Stack Overflow, etc and have not found any solution
• I updated to the latest OpenCV version and the issue is still there
• There is reproducer code and related data files (videos, images, onnx, etc)