Add a streaming interface, please

[Hassmann]

Hello Crauzer,
thank you for your work here. A quick glimpse at the code shows that you know what you are doing.

Would it be possible to pipe your XXH3 into your ZStd? To harvest a hash while compressing?
That would require a streaming interface in this repo, I guess.

I'd appreciate such a solution very much.
Or if you could put me on track to implement this myself.

Kind regards,
Andreas.