Fix audio output device selection (#17532)
Fixes #17530
Summary of the issue:
With the switch to exclusively WASAPI, selecting among more than 2 output devices did not work properly.
Description of user facing changes
Selection of output devices should now be more reliable.
Description of development approach
Fixed up the check for whether the selected device is the default output device. Also removed some unneeded initialisation parameters and constants.
Testing strategy:
Manually tested switching between 3 output devices (plus default), with various devices set as the Windows and NVDA default.
Known issues with pull request:
Some legacy winmm code remains, but this will be removed once SAPI4 support has been fixed.
