Intra process tracepoints

[cwecht]

This PR adds support for the tracepoint for intra process communication introduced in

• https://github.com/ros2/rclcpp/pull/2091
• https://github.com/ros2/ros2_tracing/pull/30

Please note, that this PR is based on https://github.com/safe-ros/ros2_profiling/pull/23.

This implementation seems to be a bit rough to me, but it should suffice as a proof of concept.

[mjcarroll]

I like this, but will probably defer on merging until the upstream intraprocess trace points land (I think they are relatively close).

[cwecht]

@mjcarroll As the intra process trace points are now merged, this PR can now considered for merging, right?