NIFI-10243: allow ControlRate to throttle on combination of data rate or flowfile rate

[markobean]

Summary

This PR modifies ControlRate processor to introduce a new mode of operation. Rate throttling can now be done by both Data Rate and FlowFile Rate. The first rate to be reached begins throttling. Documentation was improved and unit testing expanded to cover additional cases. Backward compatibility is maintained.

NIFI-10243

Tracking

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

Issue Tracking

• [X] Apache NiFi Jira issue created

Pull Request Tracking

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

Pull Request Formatting

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

Verification

Unit tests expanded to cover additional cases - both new modes of operation and older modes that were not adequately tested.

Instantiated processor in a running NiFi to perform real world testing.

Viewed documentation including new Additional Details page to verify proper representation.

Build

• [X] Build completed using mvn clean install -P contrib-check
  • [X] JDK 8
  • [X ] JDK 11
  • [X] 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

• [X] Documentation formatting appears as expected in rendered files