feat(metal): support for ray tracing + fixes

[dcvz]

Adds support for ray-tracing on Metal. Requires apple-shader-converter >= 1.1 to be installed on the computer.

apple-shader-converter requires compiling several libraries, one for the shader functions and one for the kernel dispatcher. Understanding what shader methods the HLSL requires a json file so we've create a helper that does this internally for users to not worry about it.

Additionally because loading two shaders for RT is different than the other APIs, we now have the concept of a embedded shader file with two shaders. Internally Metal checks for a header that denotes this and knows to treat it as two shaders.

This then allows the user to just load a shader as they'd expect and internally we do all the handling.