Add ability to pause/resume Remote Log Manager tasks

Once Tiered Storage is enabled, there may be situations where needed to pause uploading tasks to a remote-tier. e.g. remote storage maintenance, troubleshooting, etc.

An RSM implementation may not be able to do this by itself without throwing exceptions, polluting the logs, etc.

Could we consider adding this ability to the Tiered Storage framework? Remote Log Manager seems like a good candidate place for this; though I'm wondering on how to expose it.

Would be interested to hear if this sounds like a good idea, and what options we have to include these.

We have been considering extending RLM tasks with a pause flag, and having an MBean to switch them on demand. Another option may be to extend the Kafka protocol to expose this – but seems much moved involved.