Fill rmw's new message-info and service-info timestamp fields

[ralph-lange]

Feature request

Feature description

As basis for advanced and/or deterministic execution mechanisms in ROS Client Libraries, the message-info structs in rmw and rcl have been extended by timestamp fields to report the source and receive times of a message taken from a topic. Similar has been implemented for services. For rmw_connext, these fields should be filled with the relevant DDS meta data from Connext.

Implementation considerations

• For general discussion of improvements to rmw for deterministic execution see Improvements to rmw for deterministic execution design#259
• See the PRs Add timestamps to message info rmw#214, Service timestamps rmw#217 and Message info with timestamps support in rcl rcl#619, Implement service info structure with timestamps. rcl#627 for the corresponding changes to rmw and rcl (for the Foxy release).
• See PR Fill message_info timestamp rmw_fastrtps#368, Feature/services timestamps rmw_fastrtps#369 for how the timestamps fields are filled by rmw_fastrtps (again for the Foxy release).

[clalancette]

Closing, since with Foxy now being End-of-Life, this repository is no longer used.