fix: don't discard error in client

[littlejon85]

This resolves #9
The main issue is that the client tries to use serverError from useState and ignores the error from useAsyncData.
I'm not exactly sure how serverError is populated. I assume it has something to do with SSR. However in case without SSR the returned error is always null.

The proposed solution is to use the error from useAsyncData as initial value for useState.

const serverError = useState<TError | null>(`error-${key}`, () => error.value)

[wobsoriano]

I'll test this locally. Thanks!