Consider supporting `IAudioClient3::InitializeSharedAudioStream()` on WASAPI

[LastExceed]

The key difference to IAudioClient::Initialize() is that instead of converting your stream to whatever the engine chose for the underlying device, you actually get to specify the device's format (like in exclusive mode). This is interesting for several reasons:

• The device might support formats that the engine's auto-converter doesn't
• It potentially saves a conversion step
• It allows for lower latency (by lowering the engine's periodicity)

Not sure how important this is, just throwing it out there

[Marco-Farruggio]

Just wanted to mention, I checked the Windows docs for this, and this would raise cpal's minimum windows requirement to Windows 10, unless we only used it if we could and instead used IAudioClient::Initialize() on older versions if we didn't want to raise the minimum floor

[LastExceed]

Funnily this just came up yesterday in another issue :D Turns out we already require Win10+ anyway: #1302 (comment)

[Marco-Farruggio]

Oh that's interesting, I'll open a PR to update the docs then :)