End-to-end encrypted notifications

[zacwest]

Fixes #70. Requires https://github.com/home-assistant/core/pull/52048.

• [ ] Pass cleartext commands through, need to wire up the command manager to the register calls. Also still need to make the fcm repo handle them, or make core send them through the legacy path.
• [ ] Avoid erroring the update registration webhook, which doesn't like extra params and so the push_config is going to start erroring for.
• [ ] Tests.
• [ ] Get dependent core PR merged.

Summary

Allows decrypting notifications in the service extension.

Screenshots

Link to pull request in Documentation repository

Documentation: home-assistant/companion.home-assistant#

Any other notes

This relies on changes in core, specifically my branch of @robbiet480's branch which encrypts using the same webhook secret that we already decrypt webhook contents for.

Since we were denied the com.apple.developer.usernotifications.filtering entitlement, we need to do the cleartext commands passthrough for things like clear_notification.

[EkilDeew]

Any ideas why this never went out of draft ? I see the corresponding PR on core was stale as well. What happened ?