fix: server time delta not used in new sync - WPB-18321

[jullianm]

WPB-18321 [iOS] NSE calls timed out still passing through, server time delta not updated

Issue

This PR aims at aligning with legacy code on the serverTimeDelta usage, specifically:

1/ In NSE, we don't rely on serverTimeDelta to check if a calling event is timed out. (see legacy NotificationSession)

2/ Server time delta value is not updated upon receiving update events envelopes, we should update the value as soon as we get an envelope (see legacy NotificationStreamAsync)

Testing

N/A

Checklist

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

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UI accessibility checklist

If your PR includes UI changes, please utilize this checklist:

• Make sure you use the API for UI elements that support large fonts.
• All colors are taken from WireDesign.ColorTheme or constructed using WireDesign.BaseColorPalette.
• New UI elements have Accessibility strings for VoiceOver.

[github-actions]

Test Results

5 047 tests   5 020 ✅  5m 14s ⏱️
  728 suites     27 💤
    8 files        0 ❌

Results for commit 27e0240.

♻️ This comment has been updated with latest results.

[netbe]

LGTM

[datadog-wireapp]

Datadog Report

Branch report: fix/server-time-delta-not-used-in-new-sync
Commit report: be1c6d0
Test service: wire-ios-mono

✅ 0 Failed, 5020 Passed, 27 Skipped, 1m 49.14s Total Time