wasapi2: Increase rank to primary + 1
wasapi2 plugin should be preferred than old wasapi plugin if available because:
* wasapi2 supports automatic stream routing, and it's highly recommended
feature for application by MS. See also
https://docs.microsoft.com/en-us/windows/win32/coreaudio/automatic-stream-routing
* This implementation must be various COM threading issue free by design
since wasapi2 plugin spawns a new dedicated COM thread and all COM objects'
life-cycles are managed correctly.
There are unsolved COM issues around old wasapi plugin. Such issues are
very tricky to be solved unless old wasapi plugin's threading model
is re-designed.
Note that, in case of UWP, wasapi2 plugin's rank is primary + 1 already