MSK replicator prerequisite

Consider replicating the data in two stages - first from 2.2.1 to an intermediate upgraded cluster, then from the intermediate cluster to the 3.5.1 target. This avoids any single version jump limitations.

Export the data from the 2.2.1 source using Kafka tools like kafka-console-consumer and kafka-console-producer, then import it into the 3.5.1 target cluster. While more manual, it avoids any version incompatibilities between the source and target.