fix(kafka): overwrite the EntryId with Offset while consuming records

[WenyXu]

I hereby agree to the terms of the GreptimeDB CLA

What's changed and what's your intention?

We don't rely on the EntryId generated by mito2. Instead, we use the offset return from Kafka as EntryId. Therefore, we MUST overwrite the EntryId with RecordOffset.

Checklist

• I have written the necessary rustdoc comments.
• I have added the necessary unit tests and integration tests.
• This PR does not require documentation updates.

Refer to a related PR or issue link (optional)

#2700

[evenyag]

LGTM

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Comparison is base (8ec1e42) 85.41% compared to head (b5f3d96) 84.92%.
Report is 2 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #3148      +/-   ##
==========================================
- Coverage   85.41%   84.92%   -0.49%     
==========================================
  Files         823      823              
  Lines      134797   134927     +130     
==========================================
- Hits       115138   114592     -546     
- Misses      19659    20335     +676