tf2_geometry_msgs header file

[mfe7]

On Ubuntu 22.04 with ROS2 Humble, I was getting this error:

/home/mfe/scout_ws/src/scout_ros2/scout_base/include/scout_base/scout_messenger.hpp:21:10: fatal error: tf2_geometry_msgs/tf2_geometry_msgs.h: No such file or directory
   21 | #include <tf2_geometry_msgs/tf2_geometry_msgs.h>
      |          ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
compilation terminated.

which I fixed by adding these 3 lines to CMakeLists.txt. Not sure if that is the right way to do so.

include_directories(/opt/ros/humble/include/tf2_geometry_msgs)
include_directories(/opt/ros/humble/include/tf2)
include_directories(/opt/ros/humble/include/tf2_ros)

per this comment and the error went away.

I also was getting this warning:

In file included from /home/mfe/scout_ws/src/scout_ros2/scout_base/include/scout_base/scout_messenger.hpp:21,
                 from /home/mfe/scout_ws/src/scout_ros2/scout_base/src/scout_base_ros.cpp:12:
/opt/ros/humble/include/tf2_geometry_msgs/tf2_geometry_msgs/tf2_geometry_msgs.h:35:2: warning: #warning is a GCC extension
   35 | #warning This header is obsolete, please include tf2_geometry_msgs/tf2_geometry_msgs.hpp instead
      |  ^~~~~~~
/opt/ros/humble/include/tf2_geometry_msgs/tf2_geometry_msgs/tf2_geometry_msgs.h:35:2: warning: #warning This header is obsolete, please include tf2_geometry_msgs/tf2_geometry_msgs.hpp instead [-Wcpp]
---

but this went away when I replaced the header extension to be .hpp instead of .h