1. Fix primary-secondary replication switchover blocking by delete
replicate pchannel meta using modRevision.
2. Stop channel replicator(scanner) when cluster role changes to prevent
continued message consumption and replication.
3. Close Milvus client to prevent goroutine leak.
4. Create Milvus client once for a channel replicator.
5. Simplify CDC controller and resources.
issue: https://github.com/milvus-io/milvus/issues/44123
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Signed-off-by: bigsheeper <yihao.dai@zilliz.com>
Related to #44620
The test was flaky because pendingMessages.Len() assertion happened
before async message processing completed. Changed to assert.Eventually
to wait up to 1 second for the pending queue to drain, fixing the race
condition where actual was 1 but expected was 0.
Fixes TestReplicateStreamClient_Reconnect flakiness.
Signed-off-by: Congqi Xia <congqi.xia@zilliz.com>
