sink(ticdc): split event in mq sink if partition key updated

[CharlesCheung96]

What problem does this PR solve?

Issue Number: close #11297

What is changed and how it works?

Check List

Tests

• Unit test
• Integration test
• Manual test (add detailed scripts or steps below)
• No code

Questions

Will it cause performance regression or break compatibility?

Do you need to update user documentation, design documentation or monitoring documentation?

Release note

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