IOS/USB: Emulate Wii Speak using cubeb

Based on @noahpistilli (Sketch) PR:
https://github.com/dolphin-emu/dolphin/pull/12567

Fixed the Windows support and the heisenbug caused by uninitialized
members.

Config system integration finalized.

Source/Core/AudioCommon/CubebUtils.h

@@ -4,10 +4,16 @@
 #pragma once
 
 #include <memory>
+#include <string>
+#include <string_view>
+#include <utility>
+#include <vector>
 
 struct cubeb;
 
 namespace CubebUtils
 {
 std::shared_ptr<cubeb> GetContext();
+std::vector<std::pair<std::string, std::string>> ListInputDevices();
+const void* GetInputDeviceById(std::string_view id);
 }  // namespace CubebUtils