Add remaining Kafka and Kafka consumer metrics.

[carlosalberto]

Follow up from #2485 - this time adding the Kafka & Kafka consumer metrics from Kafka Metrics Receiver

I'd like to suggest a few changes:

• consumer_group in the name is changed to consumer (to match the producer metrics format).
• General metrics:
  • .brokers becomes UpDownCounter
  • .topic.partitions becomes UpDownCounter
  • .replicas becomes .replicas.all and UpDownCounter
  • .replicas_in_sync becomes .replicas.in-sync and UpDownCounter
• Consumer metrics:
  • .members becomes UpDownCounter

cc @mwear @jmacd

[reyang]

LGTM.

[carlosalberto]

@mwear @reyang Any opinion on the proposed changes in the PR description, and not yet applied? ;)

[reyang]

@mwear @reyang Any opinion on the proposed changes in the PR description, and not yet applied? ;)

The proposed changes from PR description look reasonable to me 👍

[carlosalberto]

Ping @dmitryax as original author/maintainer of the Kafka Metrics receiver.

[carlosalberto]

Ping @dmitryax ;)