Feature request

Feature description

I am using the nav2_behavior_tree::BtActionNode for executing a self defined ros2 action. When the action is running, action feedback is published by the action server. However, the nav2_behavior_tree::BtActionNode has not defined a feedback callback. I also could not find a way to access the action feedback at all. There was a similar issue that has been closed recently (#2839) with the same feature request.

Implementation considerations

One could define a feedback_callback within the send_goal_options in the send_new_goal() function or the feedback could be accessible within the void on_wait_for_result() function.