TCHAP: add posthog analytics

[MarcWadai]

fixes #1184

Copied from #1089 :

• Scenario 1 : appel de user A vers user B - user A doit envoyer un event CallStarted lors de l'emission d'un appel (au démarrage de l'appel)
• Scenario 2 : appel de user A vers user B - user B doit envoyer un event CallStarted lors de la réception et acceptation d'un appel (au démarrage de l'appel)
• Scenario 3 : appel de user A vers user B - user A doit envoyer un event CallEnded lors de la fin d'appel lorsque user A termine l'appel
• Scenario 4 : appel de user A vers user B - user B doit envoyer un event CallEnded lors de la fin d'appel lorsque user A termine l'appel

Checklist

• Tests written for new code (and old code if feasible).
• New or updated public/exported symbols have accurate TSDoc documentation.
• Linter and other CI checks pass.
• I have licensed the changes to Element by completing the Contributor License Agreement (CLA)

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GitGuardian id	GitGuardian status	Secret	Commit	Filename
14813093	Triggered	Generic High Entropy Secret	2452157	config.dev.json	View secret

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