UI: Add the ability to change a DualSense/DualShock 4's LED color.

Not functional yet. This is the UI & persistence side of #572.

src/Ryujinx.Common/Configuration/Hid/Controller/LedConfigController.cs

@@ -0,0 +1,15 @@
+namespace Ryujinx.Common.Configuration.Hid.Controller
+{
+    public class LedConfigController
+    {
+        /// <summary>
+        ///     Packed RGB int of the color
+        /// </summary>
+        public uint LedColor { get; set; }
+
+        /// <summary>
+        /// Enable LED color changing by the emulator
+        /// </summary>
+        public bool EnableLed { get; set; }
+    }
+}