SCB-1092 More abundant metrics information

[little-cui]

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[codecov-io]

Codecov Report

Merging #519 into master will increase coverage by <.01%.
The diff coverage is 75.75%.

@@            Coverage Diff             @@
##           master     #519      +/-   ##
==========================================
+ Coverage   59.28%   59.28%   +<.01%     
==========================================
  Files         168      170       +2     
  Lines       14099    14172      +73     
==========================================
+ Hits         8358     8402      +44     
- Misses       5159     5188      +29     
  Partials      582      582

Impacted Files	Coverage Δ
server/notify/stream.go	30.3% <0%> (-0.95%)	⬇️
server/core/backend/lease.go	82.5% <100%> (+0.44%)	⬆️
pkg/etcdsync/mutex.go	67.7% <100%> (+1.04%)	⬆️
server/core/backend/metrics.go	76.92% <100%> (+36.92%)	⬆️
server/plugin/pkg/discovery/etcd/cacher_kv.go	67.59% <100%> (+0.22%)	⬆️
server/plugin/pkg/registry/etcd/etcd.go	86.9% <100%> (+0.65%)	⬆️
server/notify/websocket.go	81.25% <100%> (+0.6%)	⬆️
server/service/event/event.go	100% <100%> (ø)	⬆️
server/plugin/pkg/discovery/metrics.go	20% <12.5%> (ø)
...rver/service/event/schema_summary_event_handler.go	25% <25%> (ø)
... and 7 more

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[coveralls]

Coverage increased (+0.03%) to 61.735% when pulling 28387c0 on little-cui:metrics into 857d993 on apache:master.