avm2: Ensure the focus is dropped when it's removed

The logic of dropping the focus when it's removed
applies not only to TextFields but for every InteractiveObject.
This patch ensures that any focus is dropped when its parent is removed.

core/src/display_object.rs

@@ -1594,6 +1594,10 @@ pub trait TDisplayObject<'gc>:
         let parent_removed = had_parent && !has_parent;
 
         if parent_removed {
+            if let Some(int) = self.as_interactive() {
+                int.drop_focus(context);
+            }
+
             self.on_parent_removed(context);
         }
     }

core/src/display_object/edit_text.rs

@@ -2114,16 +2114,6 @@ impl<'gc> TDisplayObject<'gc> for EditText<'gc> {
         self.0.write(context.gc_context).object = Some(to.into());
     }
 
-    fn on_parent_removed(&self, context: &mut UpdateContext<'_, 'gc>) {
-        if self.movie().is_action_script_3() {
-            let had_focus = self.has_focus();
-            if had_focus {
-                let tracker = context.focus_tracker;
-                tracker.set(None, context);
-            }
-        }
-    }
-
     fn self_bounds(&self) -> Rectangle<Twips> {
         self.0.read().bounds.clone()
     }