Pause & Resume Consumer

The Java client can pause & resume Pulsar consumers. We need this capability to support Blue/Green deployments with Pulsar. Is this something that is on the roadmap for `pulsar-client-node`?

Alternatively, I was thinking to simply `close()` the consumer and then re-subscribe.

将 Java 客户端的 pause/resume 行为与 Node.js consumer API 进行比较；issue 未指出任何实现文件或测试。明确预期范围是 pause/resume 还是 close-and-resubscribe，然后围绕 Blue/Green 部署期间 consumer 的行为定义验收标准。

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