NIFI-11307 Remove S2S Toolkit

[exceptionfactory]

Summary

NIFI-11307 Removes the NiFi Site-to-Site Toolkit command. The command provides limited support for sending and receiving data packets, serialized as JSON, using the Site-to-Site protocol. The command is not actively maintained, and the JSON format does not stream data, which could result in memory usage issues. The command should be removed for NiFi 2.0.

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

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Build

• Build completed using mvn clean install -P contrib-check
  • 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

[bbende]

Looks good, merging