feat: add fitEllipse and feature-tracking bindings, and support PointVectorOfVectors in drawing APIs

[giladrv]

Summary

This PR adds a few OpenCV bindings and one drawing API fix:

• add fitEllipse
• add calcOpticalFlowPyrLK
• add estimateAffinePartial2D
• extend goodFeaturesToTrack
• support PointVectorOfVectors in drawContours, fillPoly, and polylines

Why

These changes expose a few missing APIs that are useful for shape fitting and feature-tracking workflows, and fix drawing functions that currently do not accept nested point-vector inputs.

Included

• native binding updates in cpp/FOCV_Function.cpp
• TS wrapper updates in the image-processing modules
• docs updates for the added functions
• a fitEllipse example in the example app

Notes

The changes are intended to be additive and backward-compatible.

Testing

• validated the new bindings in the example app
• verified the updated drawing functions accept PointVectorOfVectors

[lukaszkurantdev]

Thanks for PR. I've merged changes, but unfortunately functions calcOpticalFlowPyrLK and estimateAffinePartial2D are outside a current opencv build used in project. To make library consented between iOS and Android I decided to remove it from the scope.