Add support for `useLayoutEffect` via `exec.layout` API

[chaance]

This PR adds an API for calling certain effects with useLayoutEffect. This should probably be used very carefully and rarely, but in certain cases it is useful.

API should be identical to calling exec directly.

I didn't add documentation yet but am happy to contribute there as well in a follow-up unless someone beats me to it.

Should be pretty straight forward, though the types are getting a bit verbose so let me know if you have any questions!