Path2D Implementation

[Pheo]

• https://developer.mozilla.org/en-US/docs/Web/API/Path2D

Adds nanosvg.h for SVG path parsing.
Known missing functionality:

1. addPath doesn't accept DOMMatrix transform
2. roundRect doesn't accept CSS-style radii array
3. ellipse doesn't handle clockwise

Called from BabylonJS/Babylon.js#16221

[CedricGuillemet]

I think we can split this PR in 2.

• merge point to be master instead of CanvasTest
• add the test example in experience.js in the CanvasTest branch