fix: deprecation warnings regarding uniform type identifiers - WPB-8778

[caldrian]

WPB-8778 Clean up code base

Issue

In Swift uniform type identifiers are a dedicated type instead of a string.
Therefore Apple deprecated various API methods and types.

This PR migrates the affected code.

Testing

No changes should be noticed on the user side, especially regarding file previews (pdf, image, video, etc.)

---

Checklist

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

---

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

    3 files    346 suites   6m 23s ⏱️
2 124 tests 2 124 ✅ 0 💤 0 ❌
2 132 runs  2 132 ✅ 0 💤 0 ❌

Results for commit d2aca89.

♻️ This comment has been updated with latest results.

[jullianm]

LGTM (just some minor comments)

[samwyndham]

Nice work! I think it would be good to understand the reason for the snapshot test failures before merging though - and ideally removing the snapshot updates. I'm just concerned there is a subtle change we are missing.