fix memory leak in jeedom_com & small code quality improvment

[Mips2648]

Description

This PR aim to fix the memory leak observed on deb11. I cannot explain why it didn't happen on others versions.
It was due to the fact that the "send async thread" was creating new thread for each new cycle (from 0.3s for most of the plugin to 30s for some like plugin-sms); and that's why the issue had small of huge impact: it depends the plugin cycle config.

So "send async thread 1" creates "send async thread 2" which will create "send async thread 3" etc; meaning that potentially none of this thread ever stop until the very last one stops which happen only when daemon is stopped; so the daemon continuously create new thread and which consume additional memories.

The correct way to do this is to have one and only one thread which will run forever until the daemon stop. To make sure the thread is stopped when the parent process (the daemon) is stopped, we flag that thread as a "daemon thread" = never-ending background task.

I took the opportunity to clean a bit the rest of the code as well.

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to fix issue in each plugin, in theory we just need to copy/past the new version of jeedom.py to the plugin BUT we should first check if there wasn't any local changes made

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Suggested changelog entry

None.

Related issues/external references

Fixes #

Types of changes

• Bug fix (non-breaking change which fixes)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)
  • This change is only breaking for integrators, not for external standards or end-users.
• Documentation improvement

PR checklist

• I have checked there is no other PR open for the same change.
• I have read the Contribution Guidelines.
• I grant the project the right to include and distribute the code under the GNU.
• I have added tests to cover my changes.
• I have verified that the code complies with the projects coding standards.
• [Required for new sniffs] I have added MD documentation for the sniff.

[Mips2648]

fix confirmed on at least 2 plugins (broadlink & rfplayer2), I'll merge this