Exporting import.meta.url does not work since once it is bundled, all files share...

Exporting import.meta.url does not work since once it is bundled, all files share the same URL and the Pool does not know which worker to spin up. It seems like a completely bundled solution will require creating workers from function strings, and that will require embedding all logic inside the worker with no external imports as far as I have been able to determine. Along with exporting workers as function strings, update BLAKE2b ckd to accept blake2b as a function string for its hashing.