Create scaffolding for Window API | fix some positioning issues in BaseComponent

engine/src/main/java/com/bartlomiejpluta/base/engine/gui/widget/ScreenWidget.java

@@ -21,11 +21,21 @@ public class ScreenWidget implements Widget {
       return screen.getWidth();
    }
 
+   @Override
+   public float getActualWidth() {
+      return screen.getWidth();
+   }
+
    @Override
    public float getHeight() {
       return screen.getHeight();
    }
 
+   @Override
+   public float getActualHeight() {
+      return screen.getWidth();
+   }
+
    @Override
    public Widget getParent() {
       return null;