Move solution and projects to src

src/Ryujinx.Ui.Common/Configuration/AudioBackend.cs

@@ -0,0 +1,14 @@
+using Ryujinx.Common.Utilities;
+using System.Text.Json.Serialization;
+
+namespace Ryujinx.Ui.Common.Configuration
+{
+    [JsonConverter(typeof(TypedStringEnumConverter<AudioBackend>))]
+    public enum AudioBackend
+    {
+        Dummy,
+        OpenAl,
+        SoundIo,
+        SDL2
+    }
+}