Support bt_file_logger_v2
Support bt_file_logger_v2 as the standard file logger is no longer built by default in bt.CPP v4 and is officially deprecated
From a very quick analysis, the main differences appear to be protocol versioning, and that tree is formatted in XML instead of flat buffers (rest is still in flat buffers)
To be honest. I first would like to get rid of the neccessity for fbl in bt_live. But that is just priorities, I guess.
Supporting the zeroMQ protocol would probably solve both issues as it sends/supplies the tree model, and can supply the action states updates. This would also remove the need for the nav2 specific ros topic
(at least for bt_live)