Description
This PR introduces a new RabbitMQHandler that provides full queue functionality using AMQP/RabbitMQ as the message broker. All queue operations are atomic and thread-safe, making it suitable for high-concurrency environments with multiple worker processes.

Checklist:

• Securely signed commits
• Component(s) with PHPDoc blocks, only if necessary or adds value
• Unit testing, with >80% coverage
• User guide updated
• Conforms to style guide