Initial project setup for llamacpp bindings

[nnance]

You can build and test the bindings by running the test script. The provider isn't integrated with the bindings yet but I wanted to get feedback on project and build setup.

[lgrammel]

I'm using vitest for testing. Here is a small example from one of the other tests:

import assert from "node:assert";
import { test, describe } from "vitest";
import { fixJson } from "./fixJson.js";

test("should handle empty input", () => {
  assert.strictEqual(fixJson(""), "");
});

Ideally we'd use the same testing lib and patterns everywhere (if this is intended to be an automated test).

[lgrammel]

I tend to put helper scripts into the bin subfolder, e.g. packages/@modelfusion-llamacpp-bindings/bin/update_submodules.sh would follow that convention here.