Harden backup restore settings

[Jacksper13]

Summary

• ignore restored wallet identity metadata that must be derived from the restored secret
• persist freshly derived XFP/XPUB after backup settings are restored
• add unit coverage for backup restore settings filtering

Validation

• python -m py_compile ports\stm32\boards\Passport\modules\tasks\restore_backup_task.py ports\stm32\boards\Passport\modules\tests\test_unit.py ports\stm32\boards\Passport\modules\tests\unit\restore_backup.py
• git diff --check --cached
• host-side stubbed regression for restore_settings_from_backup