Metrics: Producer metric overhaul + grafana dashboard

[turtleDev]

This change:

• removes false positives from producer delivery metrics ${PUBLISHER}_event_(un)delivered_total
• adds metrics for hitting quota limits on pubsub and kinesis
• adds a grafana dashboard with support for Prometheus data source.

[coveralls]

Pull Request Test Coverage Report for Build 10166318092

Details

• 142 of 229 (62.01%) changed or added relevant lines in 6 files are covered.
• 2 unchanged lines in 1 file lost coverage.
• Overall coverage increased (+0.003%) to 46.275%

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Changes Missing Coverage	Covered Lines	Changed/Added Lines	%
publisher/pubsub/error.go	0	1	0.0%
worker/worker.go	0	1	0.0%
publisher/pubsub/pubsub.go	41	83	49.4%
publisher/kinesis/kinesis.go	42	85	49.41%

Files with Coverage Reduction	New Missed Lines	%
publisher/kinesis/kinesis.go	2	70.87%

Totals
Change from base Build 10036204782:	0.003%
Covered Lines:	1149
Relevant Lines:	2483

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💛 - Coveralls