Allow to provide custom labels in metrics

[BrainHorse]

Sometimes it is more convenient to show metrics based on their labels rather than their names

[coveralls]

Pull Request Test Coverage Report for Build 11974114596

Details

• 0 of 16 (0.0%) changed or added relevant lines in 1 file are covered.
• 562 unchanged lines in 39 files lost coverage.
• Overall coverage increased (+1.4%) to 94.055%

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Changes Missing Coverage	Covered Lines	Changed/Added Lines	%
modules/metrics/src/main/scala/com/evolutiongaming/skafka/metrics/KafkaMetricsCollector.scala	0	16	0.0%

Files with Coverage Reduction	New Missed Lines	%
skafka/src/main/scala/com/evolutiongaming/skafka/producer/CreateProducerJ.scala	1	75.0%
skafka/src/main/scala/com/evolutiongaming/skafka/consumer/WithSize.scala	1	66.67%
skafka/src/main/scala/com/evolutiongaming/skafka/consumer/ConsumerRecords.scala	1	90.91%
skafka/src/main/scala/com/evolutiongaming/skafka/SecurityProtocol.scala	1	60.0%
modules/play-json/src/main/scala/com/evolutiongaming/skafka/producer/JsonProducer.scala	2	66.67%
skafka/src/main/scala/com/evolutiongaming/skafka/KeystoreType.scala	2	44.44%
skafka/src/main/scala/com/evolutiongaming/skafka/consumer/RebalanceListener1.scala	2	50.0%
skafka/src/main/scala/com/evolutiongaming/skafka/producer/RecordMetadata.scala	2	66.67%
skafka/src/main/scala/com/evolutiongaming/skafka/PartitionInfo.scala	3	40.0%
skafka/src/main/scala/com/evolutiongaming/skafka/SkafkaError.scala	3	0.0%

Totals
Change from base Build 11034997820:	1.4%
Covered Lines:	2215
Relevant Lines:	2355

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💛 - Coveralls

[Z1kkurat]

seems like it doesn't have to be called on each collect

[BrainHorse]

Good catch, changed