MQTT publish ordered processing performance improvement

[dmytro-landiak]

Pull Request description

This PR contains performance improvements for the processing of MQTT Publish packets that are sent from the clients to the TBMQ. This includes better threads usage and application resource consumption. Two queues are replaced with a single one.

General checklist

• [x] You have reviewed the guidelines document.
• [x] Labels that classify your pull request have been added.
• [x] The milestone is specified and corresponds to fix version.
• [x] Description references specific issue.
• [x] Description contains human-readable scope of changes.
• [x] Description contains brief notes about what needs to be added to the documentation.
• [x] No merge conflicts, commented blocks of code, code formatting issues.
• [x] Changes are backward compatible or upgrade script is provided.

Front-End feature checklist

• [x] Screenshots with affected component(s) are added. The best option is to provide 2 screens: before and after changes;
• [x] If you change the widget or other API, ensure it is backward-compatible or upgrade script is present.

Back-End feature checklist

• [x] Added corresponding unit and/or integration test(s). Provide written explanation in the PR description if you have failed to add tests.
• [x] If new dependency was added: the dependency tree is checked for conflicts.