Fixed errors in making the keybinding replaceable.

- Changed KeyFactory to not be a singleton
- Simplified keyBindings initializer
- Modified and simplified keyListener
- Added method to copy existing keyState
- Changed button events
- Changed to newer lambda functions
- Modified updateKey method
- Left option for multiple keys bound to one command
- Updated and wrote new JavaDoc

#story[1197]

racevisionGame/src/main/java/visualiser/app/App.java

@@ -27,6 +27,7 @@ import javafx.stage.StageStyle;
 import javafx.stage.WindowEvent;
 import javafx.util.Duration;
 import visualiser.Controllers.MainController;
+import visualiser.gameController.Keys.KeyFactory;
 
 public class App extends Application {
 
@@ -37,6 +38,7 @@ public class App extends Application {
     private Label progressText;
     private static final int SPLASH_WIDTH = 676;
     private static final int SPLASH_HEIGHT = 227;
+    public static KeyFactory keyFactory = new KeyFactory();
 
     public static App app;