iOS 17.3: AutoFill does not see main app's local directory

[keepassium]

Description In iOS 17.3, AutoFill process does not have access to the main app's local documents directory. Local key files and databases are not visible to AutoFill.

How to reproduce Steps to reproduce the behavior: see #337

Environment:

• Device: any iPhone
• OS: iOS 17.3 (works fine on iOS 17.2)
• App Version: 1.48.142

Workaround Add databases and key files to AutoFill again, as if they were external to KeePassium.

Additional context KeePassium's main app stores a reference to its sandbox. When resolved by AutoFill, that reference produces different results, depending on OS version:

• Before iOS 14: a valid URL to main app's documents, but inaccessible ("permission denied")
• iOS 14 to iOS 17.2: a valid URL to main app's documents, which works fine
• iOS 17.3: a URL to AutoFill's documents folder (which is different from that of the main app and is not visible from Files)