Freshness tracker verbosity could be improved for errors and debugging

[jyates]

For example, when a consumer is not available from burrow we dump a large error message in the logs

2022-06-29 09:03:52 ERROR [main] c.t.d.c.f.ConsumerFreshness:312 - Failed to read Burrow status for consumer example.missing.consumer. Skipping
java.io.IOException: Response was not successful: Response{protocol=http/1.1, code=404, message=Not Found, url=http://my.burrow/v3/kafka/my-cluster/consumer/example.missing.consumer/lag}
        at com.tesla.data.consumer.freshness.Burrow.request(Burrow.java:95)
        at com.tesla.data.consumer.freshness.Burrow.getConsumerGroupStatus(Burrow.java:111)
        at com.tesla.data.consumer.freshness.Burrow$ClusterClient.getConsumerGroupStatus(Burrow.java:144)
        at com.tesla.data.consumer.freshness.ConsumerFreshness.measureConsumer(ConsumerFreshness.java:307)
        at com.tesla.data.consumer.freshness.ConsumerFreshness.measureCluster(ConsumerFreshness.java:271)
        at java.util.stream.ReferencePipeline$3$1.accept(ReferencePipeline.java:193)
        at java.util.stream.ReferencePipeline$11$1.accept(ReferencePipeline.java:440)
        at java.util.stream.ReferencePipeline$2$1.accept(ReferencePipeline.java:175)
        at java.util.ArrayList$ArrayListSpliterator.forEachRemaining(ArrayList.java:1384)
        at java.util.stream.AbstractPipeline.copyInto(AbstractPipeline.java:482)
        at java.util.stream.ForEachOps$ForEachTask.compute(ForEachOps.java:290)
        at java.util.concurrent.CountedCompleter.exec(CountedCompleter.java:731)
        at java.util.concurrent.ForkJoinTask.doExec(ForkJoinTask.java:289)

But these consumers can be missing lag information if burrow has include/exclusions, making these error messages just clog the logs.

Conversely, its hard to diagnose a bug for a consumer if you don't know what freshness tracker is seeing. For example, a consumer is showing as having increasing lag but burrow & kafka both say that it is up-to-date on the latest commit (this occurred recently). If this persists past a freshness-tracker restart, something is wonky in the tracker and you would want to turn on some debug logging (even if it is verbose) to see what is going on.