ISSUE-16037: FlinkPulsarSink EXACTLY_ONCE issue

[sijie]

Original Issue: apache#16037

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Describe the bug
FlinkPulsarSink encounter issue with PulsarSinkSemantic.EXACTLY_ONCE.

To Reproduce
Steps to reproduce the behavior:

1. In apache-pulsar/conf/broker.conf, set transactionCoordinatorEnabled=true
2. Restart the broker
3. Added PulsarSinkSemantic.EXACTLY_ONCE
   
4. Encountered error Namespace not found, similar to
   [bug][java-client] Client creation fails with enableTransactions=true if topic transaction_coordinator_assign has not been created yet  apache/pulsar#15996
   Here is a screenshot of my error:
   
5. Ran command:
   sudo apache-pulsar/bin/pulsar initialize-transaction-coordinator-metadata -c pulsar-cluster-1 -cs 192.168.3.1:2181
6. And encountered another error: Transaction coordinator with id 1 not found.

Desktop

• ubuntu 20, pulsar 2.10.0, kop 2.10, flink 1.12