refactor: generate notification conversation timer update - WPB-11663

[jullianm]

WPB-11663 [iOS] Generate UNNotificationContent for conversation timer update

Key points

This PR is about generating notification content related to timer update event (enabling/disabling self destructed messages) populating the right data in the notification (title, body, sound, category..).

Testing

• Notification for timer update is correctly populated when the timer is enabled
• Notification for timer update is correctly populated when the timer is disabled

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Checklist

• Title contains a reference JIRA issue number like [WPB-XXX].
• Description is filled and free of optional paragraphs.
• Adds/updates automated tests.

[github-actions]

Test Results

    3 files      4 suites   4m 29s ⏱️
3 338 tests 3 310 ✅ 28 💤 0 ❌
3 348 runs  3 320 ✅ 28 💤 0 ❌

Results for commit 2cb70d1.

[datadog-wireapp]

Datadog Report

Branch report: refactor/generate-notification-conversation-timer-update
Commit report: d7d2dcb
Test service: wire-ios-mono

✅ 0 Failed, 3199 Passed, 28 Skipped, 2m 25.95s Total Time