EdgeDrawing: Add output of segment index for line detection

[ToFam]

Simply adds an optional output to EdgeDrawing lineDetect() for getting the edge segment each line lies on.
I need this for porting the STag library

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

[alalek]

/cc @sturkmen72

[sturkmen72]

@ToFam proposed changes looks good but i propose sturkmen72@c7951ed because in my opinion adding additional features like CihanTopal/ED_Lib#28 will be easier.

[ToFam]

@sturkmen72 Sure, whatever works best. Thank you.

[ToFam]

@sturkmen72 should I update my pr or are you going to push yours?

[sturkmen72]

@ToFam could you update your PR please. you could enrich the documentation see also sturkmen72@3a2127d

[sturkmen72]

@alalek looks good to me, please review.
@ToFam could you rebase commits into one.

[alalek]

Thank you for contribution 👍

@sturkmen72 Thank you for the review!