NIFI-15148 - Registry Clients - Support for branch creation (backend only)

[pvillard31]

Summary

NIFI-15148 - Registry Clients - Support for branch creation (backend only)

This PR takes the backend changes already submitted through #10471 and add support for all 4 flow registry clients. The UI changes would be done in a follow-up PR. This is in order to make it easier for reviewers and make progress for this improvement.

Tracking

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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 contains commits signed with a registered key indicating Verified status

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

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Build

• Build completed using ./mvnw clean install -P contrib-check
  • JDK 21
  • JDK 25

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

[exceptionfactory]

Thanks for decoupling the backend implementation pull request @pvillard31, the changes look good. If you can rebase this branch, it should be ready to merge.

For tracking, it looks like it would be helpful to close the combined PR #10471 and then create a new Jira issue for tracking the frontend implementation work.

[pvillard31]

Thanks @exceptionfactory - I rebased the PR, closed the other one and updated the JIRA description to focus on the backend changes. I'll look at the corresponding frontend changes in the future.

[exceptionfactory]

Thanks for rebasing @pvillard31, the latest version looks good. +1 merging