### Godot version

4.x

### System information

Windows 10

### Issue description

The `Search Result` panel is not correctly updated when changing the theme.

https://user-images.githubusercontent.com/66004280/208964493-d0423b78-3418-44c9-95ed-822fd34c4720.mp4



### Steps to reproduce

1. Search something
2. Change the theme

### Minimal reproduction project

--
TreeItem *item = _results_display->get_selected();
	
	Color use_color = _results_display->get_theme_color(SNAME("font_color"));
	if (!item->is_checked(0)) {
		use_color.a *= 0.5;
	}
	item->set_custom_color(1, use_color);
}
void FindInFilesPanel::_on_finished() {
	String results_text;
	int result_count = _result_items.size();
	int file_count = _file_items.size();
	if (result_count == 1 && file_count == 1) {
		results_text = vformat(TTR("%d match in %d file"), result_count, file_count);
	} else if (result_count != 1 && file_count == 1) {
		results_text = vformat(TTR("%d matches in %d file"), result_count, file_count);
	} else {
		results_text = vformat(TTR("%d matches in %d files"), result_count, file_count);
	}
	_status_label->set_text(results_text);
	update_replace_buttons();
	set_progress_visible(false);
	_refresh_button->show();
	_cancel_button->hide();
}
void FindInFilesPanel::_on_refresh_button_clicked() {