Multiple fixes:

- fix last button no longer default focused when loading keybinding dialog
- fix click and mouse exit still focused on button
- closing keybinding does not focus on chat anymore

#story[1273]

src/main/java/seng302/visualiser/controllers/ViewManager.java

@@ -221,6 +221,7 @@ public class ViewManager {
                     .getController();
                 keyBindingDialogController.setGameClient(this.gameClient);
                 keyBindingDialog.show();
+                decorator.requestFocus();
                 Sounds.playButtonClick();
             }
         }