Add R-Tree overload of beginRecording

[mattleibow]

Description of Change

Add the R-Tree overload of SKPicture.BeginRecording.

The R-Tree factory type (SkRTreeFactory) or any other SkBBHFactory types are not exposed since it is fairly complicated and not many use cases. It can be added later. For now, we just have a boolean flag indicating whether to use it or not.

Bugs Fixed

• Fixes [FEATURE] Expose existing RTree optimization option on SkPictureRecorder.BeginRecording() #2372

API Changes

class SKPicture {
    public SKCanvas BeginRecording (SKRect cullRect, bool useRTree);
}

Behavioral Changes

None.

Required skia PR

mono/skia#129

PR Checklist

• Has tests (if omitted, state reason in description)
• Rebased on top of main at time of PR
• Merged related skia PRs
• Changes adhere to coding standard
• Updated documentation