Support live mode for inspecting streams

[flippingbits]

We allow to inspect streams, i.e., view the last X records of an Apache Kafka topic.

This only offers a static view of the records in the topic that is generated when the endpoint is being called.

Additionally, we might want to add a "live mode" that streams the records from the topic to the API client, e.g., our UI, in real-time using server-sent events.