fix(error): use status.code instead of error_code for Milvus > 2.3 compatibility

[marlon-costa-dc]

Summary

• Milvus server versions > 2.3 use status.code instead of status.error_code.
• This PR updates error.rs and utils.rs to map status.code to ErrorCode properly.
• Falls back to UnexpectedError with the original code and reason if the code is unknown.

[sre-ci-robot]

[APPROVALNOTIFIER] This PR is NOT APPROVED

This pull-request has been approved by: marlon-costa-dc
To complete the pull request process, please assign yah01 after the PR has been reviewed.
You can assign the PR to them by writing /assign @yah01 in a comment when ready.

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

Details

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]

@marlon-costa-dc 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.

[mergify]

@marlon-costa-dc Please associate the related issue to the body of your Pull Request. (eg. “issue: #187”)