Enhanced metrics available from the router

The metrics available from the router shall be enhanced with the following new data:

• Per-link and global number of delayed settlements - This will provide a count of deliveries that were unsettled (in-flight) for between 1..10 seconds and those unsettled for more than 10 seconds.
• Per-link rate of delivery settlement - This will provide a five-second average rate in settlements-per-second for the link.

The relevant user is an operator or troubleshooter (Support, Engineering, etc.).

The user shall be able to identify, via CLI, console, or log, whether there is a history of delayed deliveries, or whether any existing consumer on the router network is creating delay by slow operation.