Handle options as `goja.Object` directly as opposed to exported `map[string]interface{}`

[oleiade]

At the moment we parse the options provided by the user in a two step process:

1. First, export the options goja.Object to a map[string]interface{}
2. Only then, extract and handle the options from that resulting map

This leads to what we think to be unnecessary json marshalling/unmarshalling to ensure correctness and consistency when working on a goja.Object directly might have been easier.

We probably should make a pass over the options handling code to operate that replacement 👍🏻