Investigate using the `Reflect` API instead of `Function` in Javascript

[LiveDuo]

From https://www.reddit.com/r/rust/comments/1i0hcrt/comment/m72u90d/

One thing that irks me is that it uses the equivalent of eval() and string interpolation for very basic things, like getting a property. Wouldn't it be possible to add an API like Reflect? Especially Reflect.get() and Reflect.apply() would be super useful. Instead of

Js::invoke("console.log({})", &[e.to_string().into()])
Js::invoke("{}.textContent = 'Click'", &[button.into()])
Js::invoke("return {}[{}]", &[e.into(), "keyCode".into()])

You could write something like

Reflect::apply("console.log", &[e.to_string().into()])
Reflect::set(button, "textContent", "Click")
Reflect::get(e, "keyCode")