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.

---------

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

src/Ryujinx.Input.SDL2/SDL2Mouse.cs

@@ -1,4 +1,5 @@
 using Ryujinx.Common.Configuration.Hid;
+using Ryujinx.Common.Logging;
 using System;
 using System.Drawing;
 using System.Numerics;
@@ -76,6 +77,11 @@ namespace Ryujinx.Input.SDL2
             throw new NotImplementedException();
         }
 
+        public void SetLed(uint packedRgb)
+        {
+            Logger.Info?.Print(LogClass.UI, "SetLed called on an SDL2Mouse");
+        }
+
         public void SetTriggerThreshold(float triggerThreshold)
         {
             throw new NotImplementedException();