fix: present connect screen as modal - WPB-11394

[caldrian]

WPB-11394 [iPad] Display the new conversation/connect screen modally

Issue

The connect/new conversation screen should not be embedded into the split view controller but be presented modally.
This PR fixes it.

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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.

[github-actions]

Test Results

    2 files    273 suites   8m 54s ⏱️
2 474 tests 2 472 ✅ 0 💤 2 ❌
2 476 runs  2 472 ✅ 0 💤 4 ❌

For more details on these failures, see this check.

Results for commit 67daac5.

♻️ This comment has been updated with latest results.