fix(photosDbexif): Implement dynamic detection of asset tables in photosDbexif.py

[Tokenzrey]

Previously, the script hardcoded queries to the ZASSET table (standard in iOS 13+). iOS 12 uses ZGENERICASSET. This PR implements dynamic table detection to support both schema versions and adds error handling for corrupted databases.

Changes

• Added: get_asset_table_name(db_path) helper function to check sqlite_master for ZASSET or ZGENERICASSET.
• Updated: get_photosDbexif now uses the detected table name to build the SQL query dynamically.
• Added: try-except blocks around the main query execution to prevent crashes on malformed databases.
• Result: Restores full functionality for iOS 12 backups while maintaining support for iOS 13+.

Verification & Testing

I have created a comprehensive test suite (test_photosDbexif_fix.py) to verify the fix across different schema versions.

• Test Suite: 4/4 tests passed.
• Scenarios Covered:
  • Modern iOS (iOS 13+): Verifies ZASSET detection and querying.
  • Legacy iOS (iOS 12): Verifies ZGENERICASSET detection and querying (The Fix).
  • Corrupted DB: Verifies graceful degradation when no asset table exists.
  • Bug Reproduction: Confirms the original code fails on iOS 12 schemas.

Test Output Summary:

TEST SUMMARY
================================================================================
Modern iOS (ZASSET Table)......................... [PASS]
Legacy iOS (ZGENERICASSET Table).................. [PASS]
Corrupted DB (No Asset Table)..................... [PASS]
Original Bug Demonstration........................ [PASS]
================================================================================
Total: 4/4 tests passed
[SUCCESS] ALL TESTS PASSED - photosDbexif fix is working!

Checklist

• My code follows the style guidelines of this project.
• I have performed a self-review of my own code.
• I have verified the fix with a local test script.
• The changes generate no new warnings.