enhance: Set field name as json path if not specified

[sunby]

issue: #35528

[sre-ci-robot]

[APPROVALNOTIFIER] This PR is NOT APPROVED

This pull-request has been approved by: sunby
To complete the pull request process, please assign jiaoew1991 after the PR has been reviewed.
You can assign the PR to them by writing /assign @jiaoew1991 in a comment when ready.

The full list of commands accepted by this bot can be found here.

Needs approval from an approver in each of these files:

• OWNERS

Approvers can indicate their approval by writing /approve in a comment
Approvers can cancel approval by writing /approve cancel in a comment

[mergify]

@sunby Thanks for your contribution. Please submit with DCO, see the contributing guide https://github.com/milvus-io/milvus/blob/master/CONTRIBUTING.md#developer-certificate-of-origin-dco.

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 82.14%. Comparing base (63a7c45) to head (c978295).
Report is 43 commits behind head on master.

Additional details and impacted files

@@             Coverage Diff             @@
##           master   #40419       +/-   ##
===========================================
+ Coverage   69.97%   82.14%   +12.17%     
===========================================
  Files         309     1165      +856     
  Lines       27718   179885   +152167     
===========================================
+ Hits        19396   147771   +128375     
- Misses       8322    26041    +17719     
- Partials        0     6073     +6073     

Components	Coverage Δ
Client	79.74% <ø> (∅)
Core	∅ <ø> (∅)
Go	82.27% <83.23%> (∅)

Files with missing lines	Coverage Δ
internal/proxy/task_index.go	73.55% <100.00%> (ø)
internal/util/indexparamcheck/inverted_checker.go	82.35% <ø> (ø)

... and 1472 files with indirect coverage changes

🚀 New features to boost your workflow:

• ❄ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.

[mergify]

@sunby E2e jenkins job failed, comment /run-cpu-e2e can trigger the job again.

[mergify]

@sunby E2e jenkins job failed, comment /run-cpu-e2e can trigger the job again.

[mergify]

@sunby cpp-unit-test check failed, comment rerun cpp-unit-test can trigger the job again.