WebAssembly audio output still not working fully

The QTBUG-114061 (WASM audio output) was partially fixed but there are still issues, even with the 'audiooutput' Qt Example.

Sometimes there is a single blank audio device shown in that example but then there is some audio output.  Sometimes, all the local machine's native audio output devices are shown but then there is no audio output.  In both cases if the top 'devices'  drop-down combo box is clicked and a new device or the same device is selected then the audio output stops (rather than re-selecting the device and re-initialising audio output on that device).

Interestingly when extra device enumeration and logging was added to the example, on the first run the default devices has the description: "WebAssembly audio playback device" and that is the only device. Then when QMediaDevices::audioOutputs(); is called a second time and the values are logged then a list of local native devices is listed but then outputting to any of those devices or to the default device returned by QMediaDevices::defaultAudioOutput() no longer works.