add tokenize to node client api

[jraymakers]

[This PR was previously submitted to the main duckdb repo.]

Add plumbing to expose the Tokenize method through the Node client API.

The signature of this method follows the corresponding method from duckdb-wasm. It returns an object containing two arrays of numbers, instead of an array of objects, each with two number properties (as the underlying C++ API does), presumably to reduce the number of JS objects that need to be created.

I opted to call the Tokenize method synchronously, since it's lightweight and doesn't require any database resources; it's a static method of the parser. If there's a reason to move the call to the worker thread, let me know.

In addition to exposing the method itself, the TokenType enum is also exposed. This requires some code on the C++ side in order to add the runtime enum object to the NodeDuckDB Addon, in addition to the type definition on the TypeScript side.

A basic unit test suite is included.

[Mytherin]

Thanks! LGTM