[Access] Improve subscription `Streamer` functionality to graceful shutdown on demand

[Guitarheroua]

Problem Definition

The Streamer now should handle one more extra block to gracefully shut the subscription (see discussion in PR). There should be a way to send the reply and shut down the subscription immediately after that on demand.

For this, the Streamer, and perhaps other subscription core functionalities, should be improved to react to shutdown signals and handle replies and subscriptions properly.

Definition of Done

• Implement and update unit and functional tests to ensure that the new functionality works properly and the old one works as previously.

[github-actions[bot]]

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