sink(ticdc): fix incorrect default field

[wk989898]

What problem does this PR solve?

Issue Number: close #12037

What is changed and how it works?

OriginDefaultValue is used as the column value when the default value is invisible.
It should not be used as the default field.

Check List

Tests

• Unit test
• Integration test

Questions

Will it cause performance regression or break compatibility?

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

Release note

fix incorrect `default` field.

[ti-chi-bot]

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