sink(ticdc): refine sink interface and add init method (#5196)

[ti-chi-bot]

This is an automated cherry-pick of #5196

What problem does this PR solve?

We need to clean up the old values of the table checkpoint, otherwise when the table is dispatched back again, it may read the old values. See: #4464 (comment).
To guarantee the value is cleared, we clear old values when the table pipeline is created.

Issue Number: close #5197 ref #4464

What is changed and how it works?

refine cdc sink interface
add an init method to init and clear up old values
remove drawback from buffer sink

Check List

Tests

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

Release note

`None`.

[ti-chi-bot]

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[sdojjy]

/run-unit-test
/run-verify-test

[sdojjy]

/run-unit-test
/run-verify-test