Allow passing cap to VideoCapture constructor

[la-we]

Currently working on a project where i need functionality of passing explicit CAPs to VideoCapture, figured i contribute a little.

[UrielCh]

Please try to match parameters names from openCV:

VideoCapture(const String &filename, int apiPreference=[CAP_ANY])

Opens a video file or a capturing device or an IP video stream for video capturing with API Preference.

the parametere is named apiPreference, not cap

[UrielCh]

I live you check why some CI task fail. https://github.com/UrielCh/opencv4nodejs/actions/runs/10590201924/job/29348071635

[la-we]

Tests should pass now on all OSes

[UrielCh]

the test still failed on macos.

[UrielCh]

LGTM