feat: add support for optional 'errors' field in MobileDocument

[FlavPMU]

Add support in order to read Mdoc issued by "France-Identite" Wallet : https://playground.france-identite.gouv.fr/doc/marketplace/wallets/fin/

• Add optional 'errors' parameter to MobileDocument.init()
• Include 'errors' field in dump() output when present
• Add comprehensive test suite (test_09_errors_field.py)
• Fixes TypeError when parsing Device Response with status != 0
• ISO 18013-5 compliance for error handling
• All tests pass (36/36)
• fix: handle simple values in list elements within _decode_claims When elementValue is a list (e.g., nationality: ['FR']), elements can be simple values (strings, numbers) instead of dicts. Added check to handle both cases instead of assuming all elements have .items() method.

See docs/FIX_ERRORS_FIELD.md for detailed documentation