Avoid copy of memory for state changes by using .subarray()

[vipertechofficial]

Used subarray method whenever possible and added a method to reset the object, enabling the same object to be reused properly.

[jungomi]

Thanks, avoiding a copy is always nice 👍

For the reset, as we based the streaming interface on the API of Hash from the Node.js crypto module, there is no way to reset it and it is expected to create a new Hasher for it.
I can see the interest in having it, but if it should be added, that requires writing extensive tests for it, change the type definitions in types.d.ts and include that information in the README. So I would suggest to move the reset functionality to a separate PR, if that's really something that should be added, and keep this PR just for the subarray change.