feat: introduces API v14 to fetch new cells feature config - WPB-22364

[jullianm]

WPB-22364 [iOS] Support backend url configuration from feature flag settings

Issue

This PR introduces API v14 which is required to fetch wire cells backend URL from a newly introduced feature config.

A key change in this PR is to resolve the cells server URL dynamically since we now get its value after pulling all the resources during initial sync.

To avoid dealing with optionals in many parts of the codebase and keep the structure as close as it is currently, the solution was to inject a URL resolver closure in the factory which will be invoked at runtime by the RestAPI and the AWSClient.

Note: at the time of this PR, API v14 is still under development

Testing

• on dev env (IMAI), fresh launch the app with API v13 or below, cells related features should be hidden to the user.
• open dev tool, set preferred API version to 14, open the app again, cells features should now be visible.

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

    8 files  1 062 suites   9m 22s ⏱️
8 255 tests 8 225 ✅ 27 💤 3 ❌
8 256 runs  8 229 ✅ 27 💤 0 ❌

For more details on these failures, see this check.

Results for commit 6aa6337.

♻️ This comment has been updated with latest results.

[samwyndham]

Nice work. I've added a comment for a small change to do in the AWS client. Feel free to discuss.

[samwyndham]

Nice work!