Fix saving wrong edited scene state when switching scene tabs

When creating a new scene, the scene tab will actually switch to the newly created one.
Also worth noting that switching scene tabs saves state (by `save_edited_scene_state`).

When trying New Scene again, the previously empty scene tab will be removed.

So the correct logic is: switch the tab save state first, and then remove the previous
empty scene tab. To prevent `current_edited_scene` from being incorrect when saving state.

editor/editor_node.cpp

@@ -3664,6 +3664,8 @@ void EditorNode::fix_dependencies(const String &p_for_file) {
 
 int EditorNode::new_scene() {
 	int idx = editor_data.add_edited_scene(-1);
+	_set_current_scene(idx); // Before trying to remove an empty scene, set the current tab index to the newly added tab index.
+
 	// Remove placeholder empty scene.
 	if (editor_data.get_edited_scene_count() > 1) {
 		for (int i = 0; i < editor_data.get_edited_scene_count() - 1; i++) {
@@ -3674,9 +3676,7 @@ int EditorNode::new_scene() {
 			}
 		}
 	}
-	idx = MAX(idx, 0);
 
-	_set_current_scene(idx);
 	editor_data.clear_editor_states();
 	scene_tabs->update_scene_tabs();
 	return idx;
@@ -3834,6 +3834,12 @@ Error EditorNode::load_scene(const String &p_scene, bool p_ignore_broken_deps, b
 	// If we are, we'll edit it after the restoration is done.
 	if (!restoring_scenes) {
 		push_item(new_scene);
+	} else {
+		// Initialize history for restored scenes.
+		ObjectID id = new_scene->get_instance_id();
+		if (id != editor_history.get_current()) {
+			editor_history.add_object(id);
+		}
 	}
 
 	// Load the selected nodes.