fix(consensus): preserve SyncLog retry ordering

[Caideyipi]

Description

Fix the SyncLog retry ordering regression covered by this PR.

When the follower encounters the first retryable write error in a batch, it now stops applying subsequent requests immediately. The remaining response entries are filled with WRITE_PROCESS_REJECT statuses indicating that they must wait for the previous request to complete. The leader can still retry the whole batch without allowing later requests to overtake the failed request.

The regression test now also verifies the deferred status and message for the unprocessed request.

Verification

• ReplicateTest#syncLogWriteProcessErrorRetryPreservesRequestOrderTest
• ReplicateTest#syncLogWriteProcessErrorTriggersLeaderRetryTest
• Maven Spotless and Checkstyle
• Consensus reactor test-compile with the Chinese locale

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This PR has:

• been self-reviewed.
• added unit tests to cover the regression.

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Key changed/added classes

• IoTConsensusServerImpl
• ReplicateTest