NIFI-10109 Preserve Field Order in JsonTreeReader

[exceptionfactory]

Summary

NIFI-10109 Replaces usage of HashMap with LinkedHashMap in JsonTreeRowRecordReader and MapRecord to preserve input field order read from input JSON Objects nodes. This approach maintains a deterministic internal representation of objects.

Tracking

Please complete the following tracking steps prior to pull request creation.

Issue Tracking

• Apache NiFi Jira issue created

Pull Request Tracking

• Pull Request title starts with Apache NiFi Jira issue number, such as NIFI-00000
• Pull Request commit message starts with Apache NiFi Jira issue number, as such NIFI-00000

Pull Request Formatting

• Pull Request based on current revision of the main branch
• Pull Request refers to a feature branch with one commit containing changes

Verification

Please indicate the verification steps performed prior to pull request creation.

Build

• Build completed using mvn clean install -P contrib-check
  • JDK 8
  • JDK 11
  • JDK 17

Licensing

• New dependencies are compatible with the Apache License 2.0 according to the License Policy
• New dependencies are documented in applicable LICENSE and NOTICE files

Documentation

• Documentation formatting appears as expected in rendered files

[emiliosetiadarma]

Was able to run a build that worked well, and run the tests. Was also able to verify that it worked with a sample flow!

[exceptionfactory]

Thanks for the review @emiliosetiadarma!

[markap14]

Thanks @exceptionfactory LGTM +1 merged to main