[FEATURE] Add function to SkiaSharp.Harfbuzz for getting shaped text paths

[ScrubN]

Is your feature request related to a problem? Please describe.

Currently, there is no shaped equivalent to SKPaint.GetTextPath(), which can be inconvenient in scenarios that utilize CanvasExtensions.DrawShapedText() and require drawing an outline around the text.

Describe the solution you'd like

An extension method for SKFont that returns the shaped path of a text input. To remain consistent with CanvasExtensions.DrawShapedText(), the primary method signature would ideally be along the lines of:

SKPath GetShapedTextPath(this SKFont paint, SKShaper shaper, string text, float x, float y, SKTextAlign textAlign)

Describe alternatives you've considered

This functionality could just be implemented within my own projects, however I believe it would benefit the community if it were included within SkiaSharp.Harfbuzz.