Disable keyboard controller input while swkbd is open (foreground) (second attempt) (#6808)

* Block input updates while swkbd is open in foreground mode

* Flush internal driver state before unblocking input updates

* Rename Flush to Clear and remove unnecessary attribute

* Clear the driver state only if the GamepadDriver isn't null

src/Ryujinx.Input/IGamepadDriver.cs

@@ -33,5 +33,11 @@ namespace Ryujinx.Input
         /// <param name="id">The unique id of the gamepad</param>
         /// <returns>An instance of <see cref="IGamepad"/> associated to the gamepad id given or null if not found</returns>
         IGamepad GetGamepad(string id);
+
+        /// <summary>
+        /// Clear the internal state of the driver.
+        /// </summary>
+        /// <remarks>Does nothing by default.</remarks>
+        void Clear() { }
     }
 }