fix(cdc): avoid serde the schema field in the Debzium connector

[StrikeW]

I hereby agree to the terms of the RisingWave Labs, Inc. Contributor License Agreement.

What's changed and what's your intention?

Resolve #12535 (comment)

The provided JSON converter will output the schema field in the JSON which is unnecessary to source parser, we use a customized JSON converter to avoid outputting the schema field to save cpu.

Checklist

• I have written necessary rustdoc comments
• I have added necessary unit tests and integration tests
• I have added fuzzing tests or opened an issue to track them. (Optional, recommended for new SQL features Sqlsmith: Sql feature generation #7934).
• My PR contains breaking changes. (If it deprecates some features, please create a tracking issue to remove them in the future).
• All checks passed in ./risedev check (or alias, ./risedev c)
• My PR changes performance-critical code. (Please run macro/micro-benchmarks and show the results.)

• My PR contains critical fixes that are necessary to be merged into the latest release. (Please check out the details)

Documentation

• My PR needs documentation updates. (Please use the Release note section below to summarize the impact on users)

Release note

If this PR includes changes that directly affect users or other significant modifications relevant to the community, kindly draft a release note to provide a concise summary of these changes. Please prioritize highlighting the impact these changes will have on users.

[tabVersion]

I am ok with the change but why retain the schema field?

[StrikeW]

I am ok with the change but why retain the schema field?

In #12535 the CREATE SOURCE requires the payload field since its schema has a (payload jsonb) column.

[codecov]

Codecov Report

Merging #13212 (c4dc700) into main (73dcbc2) will increase coverage by 0.00%.
Report is 1 commits behind head on main.
The diff coverage is n/a.

@@           Coverage Diff           @@
##             main   #13212   +/-   ##
=======================================
  Coverage   68.14%   68.15%           
=======================================
  Files        1513     1513           
  Lines      256990   256990           
=======================================
+ Hits       175135   175139    +4     
+ Misses      81855    81851    -4     

Flag	Coverage Δ
rust	68.15% <ø> (+<0.01%)	⬆️

Flags with carried forward coverage won't be shown. Click here to find out more.

see 8 files with indirect coverage changes

📣 We’re building smart automated test selection to slash your CI/CD build times. Learn more