[tools] Scraper to tag log lines when router link state costs are stable or not

Scraper synthesizes a view of routing protocol link state costs from multiple log files. This view identifies a stable state when all routers are reachable and when all routers agree on link state costs.

Identifying when link costs are in flux may help identify periods of instability and be the root cause of unexpected message dispositions.

DISPATCH-1183 exposes some of the inner workings of the link state cost calculation on a ring of 26 routers.

The proposal for this issue is to highlight the time-of-day fields for AMQP sent or received when the costs are unstable.