This issue will track the work needed to complete ROS2 Topic Statistics.

Dependencies

• Define statistics message in `rcl_interfaces' (Add new messages for topic statistics rcl_interfaces#98)
• Move libstatistics_collector to separate repository (Moved libstatistics_collector folder from system_metrics_collector ros-tooling/libstatistics_collector#2)
• Add libstatistics_collector to ros2.repos file (Add topic statistics dependency #897)
• Fix 'libstatistics_collector' Windows issues (Fix Windows Compiling Issues ros-tooling/system_metrics_collector#137)

Integration with rclcpp

• Define Topic Statistics classes in rclcpp (Topic Statistics: Add SubscriptionTopicStatistics class rclcpp#1050)
• Integrate TopicStatistics classes in subscriber handle_message (Integrate topic statistics rclcpp#1072)
• Add SubscriptionOptions for Topic Statistics (Add SubscriptionOptions for topic statistics rclcpp#1057)
• Add NodeDefault option for enabling topic statistics (Add NodeDefault option for enabling topic statistics rclcpp#1074)
• Add received message age measurement to Topic Statistics (Add received message age metric to topic statistics rclcpp#1080)