Add AddingTrailingDataSubscriber to allow users to send additional data t…

[zoewangg]

…o the downstream subscriber

Motivation and Context

There are use-cases where we want to send trailing data on top of what the publisher publishes. For example, in async signing code path, we always send a trailing empty frame.

Modifications

• Add AddingTrailingDataSubscriber to allow users to send trailling to the downstream subscriber
• Expose SdkPublisher#addTrailingData

Testing

Added TCK tests and unit tests.

Screenshots (if appropriate)

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)

Checklist

• I have read the CONTRIBUTING document
• Local run of mvn install succeeds
• My code follows the code style of this project
• My change requires a change to the Javadoc documentation
• I have updated the Javadoc documentation accordingly
• I have added tests to cover my changes
• All new and existing tests passed
• I have added a changelog entry. Adding a new entry must be accomplished by running the scripts/new-change script and following the instructions. Commit the new file created by the script in .changes/next-release with your changes.
• My change is to implement 1.11 parity feature and I have updated LaunchChangelog

License

• I confirm that this pull request can be released under the Apache 2 license

[sonarcloud]

SonarCloud Quality Gate failed.   

0 Bugs
0 Vulnerabilities
0 Security Hotspots
3 Code Smells

77.0% Coverage
3.9% Duplication

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