Add option to change controller LED color (#572)

This allows the user to change the controller LED while using Ryujinx.
Useful for PS4 and PS5 controllers as an example.

You can also use a spectrum-cycling Rainbow color option, or turn the LED off for DualSense controllers.

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Co-authored-by: Evan Husted <greem@greemdev.net>

src/Ryujinx/Input/AvaloniaMouseDriver.cs

@@ -3,6 +3,7 @@ using Avalonia.Controls;
 using Avalonia.Input;
 using Ryujinx.Input;
 using System;
+using System.Collections.Generic;
 using System.Numerics;
 using MouseButton = Ryujinx.Input.MouseButton;
 using Size = System.Drawing.Size;
@@ -134,6 +135,8 @@ namespace Ryujinx.Ava.Input
             return new AvaloniaMouse(this);
         }
 
+        public IEnumerable<IGamepad> GetGamepads() => [GetGamepad("0")];
+
         public void Dispose()
         {
             if (_isDisposed)