[Volunteer] Improper word usage in Plugin Logging-Kafka configuration#namesrvAddr

### Volunteer help

In Kafka, we always interact with the broker, so the parameter for setting the broker address should be called `bootstrap server` rather than `namesrvAddr`. `namesrvAddr` is a concept specific to RocketMQ, and I believe mixing these terms could cause confusion.

Start in the Plugin Logging-Kafka configuration and trace every use of `namesrvAddr`. Confirm whether the setting appears in code, configuration examples, or documentation; done means Kafka-facing terminology consistently refers to the broker bootstrap server without the RocketMQ-specific name.

Written by the indexing model from the issue text.