Rust bindings

[Code-Solver]

Describe your changes

Added Rust bindings.

Checklist before requesting a review

• I have performed a self-review of my code.
• If it is a core feature, I have added thorough tests.
• I have added thorough documentation for my code.
• I have tagged PR with relevant project labels. I acknowledge that a PR without labels may be dismissed.
• If this PR addresses a bug, I have provided both a screenshot/video of the original bug and the working solution.

Demo

I have added README to include demos showcasing the usage.

Notes

I have tested these Rust bindings only on macOS and Linux (Ubuntu).

[cosmic-snow]

Just a heads-up: I'm not sure whether this is going to get any traction. There was another PR quite a while ago (#966) and it didn't go anywhere.

You might want to join the Discord and talk to someone with a say directly.

[AndriyMulyar]

@Code-Solver Can you recommend anyone to review this on the rust side?

[cebtenzzre]

@Code-Solver If you can join the GPT4All Discord and ping me (@cebtenzzre), I'd like to discuss this PR.

My main concern is that of all of the community contributed language bindings we have, only one is actively maintained and confidently known to work - the node.js bindings. Our python binding is the only one we officially support. This binding can certainly live in your fork, but to accept these changes it would be important for us to have some confidence that you are interested in actively maintaining it in the long term, and updating it whenever the llmodel_c API introduces a breaking change.

[cebtenzzre]

As mentioned on Discord, CI integration and/or unit tests would significantly improve the chances of this PR being accepted.