Kafka-UI connection count and other client metrics

[odoszhanov]

Hey! Is there a way to check the connections count coming from Kafka-UI? We might needed these metrics to have better observability from client side. Imagine if you're using MSK-Serverless which do not provide cluster level metrics on connections count (but do have a quota limit for it), additional client metrics might be useful to see if you're approaching limits.

[Haarolean]

There are messages polling metrics available: #4069, that's perhaps all there is