Improved logging for insight stat packets
Insight support for jobs:
* Add insight Groups to Application singleton
* Put JobQueue metrics into "jobq" Group
* Add queued time to Job
* Add per-type Job queue time metrics
* Add per-type Job execution time metrics
* Break JobQueue sources out of the namespace
* Use free function to create the JobQueue
Fix insight object lifetimes in Group
Fix crash on exit in ~InboundLedger
Fix a slot tracking issue, improve "print peerfinder" and add documentation
Remove closing count tracking
[FOLD] Properly track slots.