This allows us to work with a more go way of working with conditional
branching.

If no named exports are available, we want to try and convert the
default export to named exports. This allows users to work with
namespaced objects even through the module hasn't been setup to work in
that way. This is how node works too.

This is to stay consistent with other areas of the codebase
(e.g. toESModuleExports). There could be a valid case where we want
named to be an empty slice and default be non-nil, and not use this
feature to convert from default to namespace exports.

It needs to be of length 0 to allow for append from 0.

This is a better and safer way to work with an interface{} type when we
need to retrieve the property values from the object. Since the
underlying type of Default could be anything, including a sobek.Value,
it's better to retrieve it as a sobek.Object instead of a casting.

This will allow us to create other tests under the StarImport domain.