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The registration manager of an unregistered controller should attempt to re-register with the active controller. This is to prevent accidental unregistrations. The intention for unregistration is for it to occur after the operator decommissions a node which will no longer be part of the kafka cluster, and is not expected to return. 

Metadata Quorum Tool Changes

This new flag means that the remove-controller command could send two RPCs to the active controller, one to remove the node from the KRaft voter set, and another to remove the node's registration. The implementation of this command should be able to handle cases where:

• The node is part of the voter set and is registered
• The node is part of the voter set and is not registered
• The node is not part of the voter set and is registered
• The node is not part of the voter set and is not registered

Test Plan

Add an integration test for unregistering a controller in both static quorum and dynamic quorum clusters. 

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