Evaluations can be promises and those should not be resolved

[borkdude]

e.g.

(Promise.resolve 1)

should return that promise but when you evaluate it, the result via the API is a promise with the result and then the returned promise is in turn resolved. This is JS behavior: nested promises are flattened. I.e. Promise<Promise<T>> cannot exist.

microsoft/TypeScript#27711

As such we should wrap evaluation results.