More typography updates

[davepagurek]

Changes

• Adds back alpha in textToPoints using a getter to avoid upfront extra costs if it's not
  • Aliases it from an angle property, possibly more understandable?
• Adds a convenience function for WebGL, font.textToModel(), to make an immediately renderable 3D model, using the same API as textToPoints
• Let WebGL mode load from Google Fonts

Screenshots of the change:

PR Checklist

• npm run lint passes
• Inline documentation is included / updated
• Unit tests are included / updated

[davepagurek]

Looks like there's not a good way to force Google Fonts to serve ttfs unfortunately--it'll do it if you don't supply a user agent header, but we can't do that with fetch without breaking CORS and not being able to read the response.

So if we want to get Typr working on a google font, we'll probably have to decode the woff2 files, which would be a quite big dependency, which we probably also don't want. Alas. We'll see what the implementation of photopea/Typr.js#7 in Typr is, maybe if it's able to be loaded on-demand it could be ok?