Add Diagnostics to ros2_control [HUMBLE]

[zkeyg]

Is your feature request related to a problem? Please describe.
Hi I am trying to set up a system with ros2_control. I met the issue #1185. I noticed that @bmagyar mentioned that ros2_control has its own diagnotisc published to /diagnostics. However I went back to my setup and realized that I was using Ros2-humble. In ros2_control humble, diagnostics has been reverted (#1015) due to ros2/rclcpp#2183.

Describe the solution you'd like
Since ros2/rclcpp#2183 has been merged, is it able to re-enable diagnsotics in ros2_control?

Describe alternatives you've considered

Additional context

[bmagyar]

Oh, thanks for following up on this!
It is ABI breaking but I am sort of open to this... What do you gents think? @destogl @christophfroehlich @saikishor

[christophfroehlich]

gazebo_ros2_control still is built for humble? Otherwise it will break.