Improvements to input and input configuration in the GUI. (#849)

* Improvements to input and input configuration in the GUI

* Requested changes

* nits

* more nits

Ryujinx.Common/Configuration/Hid/InputConfig.cs

@@ -0,0 +1,20 @@
+namespace Ryujinx.Common.Configuration.Hid
+{
+    public class InputConfig
+    {
+        /// <summary>
+        /// Controller Device Index
+        /// </summary>
+        public int Index { get; set; }
+
+        /// <summary>
+        ///  Controller's Type
+        /// </summary>
+        public ControllerType ControllerType { get; set; }
+
+        /// <summary>
+        ///  Player's Index for the controller
+        /// </summary>
+        public PlayerIndex PlayerIndex { get; set; }
+    }
+}