refactor: integrate new initial sync - WPB-10801

[johnxnguyen]

WPB-10801 [iOS] Integrate new slow sync

Issue

In this PR we integrate the new initial sync by:

• initializing and injecting SyncAgent into the ZMUserSession
• replace calls to the SyncStatus with calls to SyncAgent

If the developer flag newInitialSync is off (the default), then the SyncAgent will execute legacy code paths via the SyncStatus. If it is on, it will run the new initial sync, then continue with the legacy incremental sync.

Integrating the new incremental sync will follow in a subsequent PR.

Testing

To check the legacy code paths are still in tact, install the app fresh and log in and use the app as normal. To test the new code paths, enabled the flag via the developer menu.

Issues to look for include infinite sync, getting stuck when logging in or registering a client (including deleting a client).

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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.

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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.

[netbe]

looks good, adding some thoughts and concerns about processing buffered events in legacy

[netbe]

LGTM;)

[github-actions]

Test Results

    5 files      6 suites   5m 33s ⏱️
4 728 tests 4 698 ✅ 28 💤 2 ❌
4 738 runs  4 710 ✅ 28 💤 0 ❌

For more details on these failures, see this check.

Results for commit 7fefd5b.

♻️ This comment has been updated with latest results.

[datadog-wireapp]

Datadog Report

Branch report: refactor/integrate-sync-agent-wpb-10801
Commit report: d3e339c
Test service: wire-ios-mono

✅ 0 Failed, 4485 Passed, 28 Skipped, 2m 1.74s Total Time

[netbe]

Good changes with the Components, I left some more comments just ping me when I need to look again

[netbe]

all good, just adding a last point

[samwyndham]

Un-assigning myself as this PR is already approved. Feel free to add be back