No ASIO support in 0.5.0

[TonyBeswick]

I see default ASIO support was removed in 0.5.0: https://github.com/spatialaudio/python-sounddevice/issues/496 and there was a call out on that issue for anyone who's relying on ASIO, sorry I'm a bit late - I'm using it.

Our use case: We've got a simulation system that outputs multi-channel audio-band signals for embedded product testing. We're using ASIO because the audio interface we're using (Presonus Studio 1824c) only appears to offer multi channel output via the ASIO driver (I could be mistaken) and the low latency is of some benefit too.

We're not too keen on manually placing .dlls as a workaround, as we'd like to keep our deployments easy with just pip install commands.

I see this comment raised the idea of using extras, so ASIO support can be added by installing with sounddevice[asio]. This would be a great solution for our use case - if it can be made to work.