Reference types

[domoritz]

Check whether https://rustwasm.github.io/docs/wasm-bindgen/reference/reference-types.html helps with performance.

[domoritz]

Needs drager/wasm-pack#937 or drager/wasm-pack#888 or switching away from wasm-pack.

[domoritz]

Got it working with just wasm-bindgen-cli (see https://github.com/domoritz/arrow-wasm/tree/dom/reference-types) but the setup isn't fun and we need to validate the performance.

[serprex]

@domoritz my PR has since merged