Add Spring.GetSoundDevices.

[saurtron]

Work Done

• Add Spring.GetSoundDevices(), returning an array of device names.

Remarks

• Games having to parse infolog.txt, that seems awkward and fragile.
• Thought about naming it Spring.GetSoundDeviceNames(), in case later we want to return tables with more information about devices (number of channels...), but I thought maybe later we can just add another argument to make it return everything: Spring.GetSoundDevices(full).
• Thought about putting this at Platform, but I guess this is not static since devices can come and go.

[sprunk]

Perhaps do it the full way already and return tables?

{
  { .name = "dev1", },
  { .name = "dev2", },
  -- ...
}

[lhog]

I know it's a copy-paste code from the previous implementation, but it's hard to read and comprehend if it works as it should. Would be great to rewrite it to something more comprehensible like a combo of std::find_if / std::find_if_not

[lhog]

Overall LGTM