Extract text rendering to a ThreeJS object

[lojjic]

Text3DFacade's underlying implementation should be extracted to a subclass of THREE.Mesh (without a dependency on troika-3d if possible). This would allow it to be used by itself in other projects and frameworks (AFrame, react-three-fiber, etc.) that could benefit from its advantages over other text implementations.

[lojjic]

Done! There is now a TextMesh class which can be used standalone in any Three.js project or framework; it only depends on the few utilities it needs and omits the Troika framework code.

Those wanting to use it outside the Troika framework may import src/three/TextMesh.js directly, or the build also now produces dist/textmesh-standalone.<esm|umd>.js bundles in the published package.

[lojjic]

Demo using react-three-fiber: https://codesandbox.io/s/troika-3d-text-via-react-three-fiber-ntfx2?fontsize=14