[BUG] un-necessary register producer in persistentTopic

[aloyszhang]

Describe the bug
KafkaTopicManager will registers a producer in PersistentTopic every time KafkaTopicManager#getTopic invoked.
However KafkaTopicManager#getTopic is invoked from not only ProduceRequest, but also many other places like KafkaRequestHandler#finkBroker() or KafkaRequestHandler#handleListOffsetRequestV1AndAbove etc.

Expected behavior
Kop should register producer only when the request is ProduceRequest