Tracking Issue for Rust Bindings

[scott-wilson]

The bindings are an experiment based on the cxx Rust crate, with my initial implementation here: https://github.com/vfx-rs/oiio-bind

The current goal is to create a very minimal implementation of the ImageInput and ImageOutput as a prototype. This will be done in two stages:

1. Create the oiio-sys crate. The majority of the work has been done in Create unsafe sys crate vfx-rs/oiio-bind#29.
2. Create the oiio crate. This has yet to start, but the goal is the API should look almost exactly like the current C++ API, except for error handling (Use Rust's Result type).

[scott-wilson]

Initial attempt at wrapping TypeDesc in Rust: #4643