KAFKA-19542: Consumer.close() does not remove all added sensors from Metrics

[kirktrue]

The intention of the Consumer API is that after close(), metrics() should return an empty map of metrics. The lifecycle management of the various metrics managers in the consumer is inconsistent. Some managers remove all the metrics that were created, some registries remove some of them, and some don't make any effort to remove the metrics at all.

This change introduces AbstractConsumerMetricsManager as a shared base class for consumer metrics managers, consolidating the steps of metric registration and cleanup logic, as well as unit tests to ensure that the different metrics managers perform the cleanup step.