wasapi: Add a property for trying the AudioClient3 API

wasapi: Add a property for trying the AudioClient3 API

The AudioClient3 API is only available on Windows 10, and we will
automatically detect when it is available and use it.

However, using it for capturing audio with low latency and without
glitches seems to require setting the realtime priority of the entire
pipeline to "critical", which we cannot do from inside the element.

Hence, we can only enable that by default for wasapisink since
apps should be able to safely set the low-latency property to TRUE if
they need low-latency capture or playback.