Support safe removal of multiple cluster nodes

[CRZbulabula]

Summary

• Validate DataNode removals per affected RegionGroup: removed replicas must be less than the replica count for weak-consistency protocols, while twice the removed replica count must be less than the replica count for Ratis.
• Migrate at most one replica per RegionGroup in each round, allowing one multi-DataNode request to complete whenever the safety thresholds are satisfied.
• Apply the same safety rule to ConfigNodeGroup removals while accounting for queued and in-progress removals and rejecting duplicate requests.
• Add localized diagnostics plus focused unit and integration coverage.

Testing

• mvn test -pl iotdb-core/confignode -Dtest=NodeRemovalSafetyTest,RemoveDataNodesProcedureTest,RemoveConfigNodeProcedureTest,ProcedureManagerTest
• mvn verify -DskipUTs -Dit.test=IoTDBRemoveDataNodeNormalIT#success1C5DRemoveTwoDataNodesSharingRegionUseTableSQL -DfailIfNoTests=false -Dfailsafe.failIfNoSpecifiedTests=false -pl integration-test -am -PClusterIT -P with-integration-tests
• mvn verify -DskipUTs -Dit.test=IoTDBRemoveConfigNodeNormalIT#testRejectRemovingOneOfTwoConfigNodes -DfailIfNoTests=false -Dfailsafe.failIfNoSpecifiedTests=false -pl integration-test -am -PClusterIT -P with-integration-tests
• mvn test-compile -DskipTests
• mvn test-compile -P with-zh-locale -DskipTests