Migration to ROS2 Humble

[TitouanTyack]

Hi,

Thank you for sharing your velocity estimation code. As I'm working on ROS2 Humble I've started migrating the code. I have already converted the radar only velocity estimation. I was able to try it with a TI AWR 1843 and it seems to work normally.
Would you be interested if I made a pull request?

Thanks again.
Titouan