G-API: Move OneVPL arguments parser to generic place

[TolyaTalamanov]

System information (version)

• OpenCV => 4.6
• Operating System / Platform => ALL
• Compiler => ALL

Detailed description

Move cv::gapi::wip::onevpl::CfgParam create_from_string(const std::string &line); from there to more generic place in gapi module in order to make it reusable for all application that are using onevpl feature.

Steps to reproduce

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