Replace the vat_rate info with a call to `eurovat` (and .update)

[dgtlmoon]

Replace the vat_rate info with a call to https://github.com/airgproducts/eurovat (and .update())

that way a whole lot of old dangerous code does not need to be in this library

[dgtlmoon]

import eurovat
from eurovat.registry import VatRuleRegistry


def update_vat_data_if_needed(max_age_hours=24, verbose=True):
    """
    Update VAT data if cache doesn't exist or is older than max_age_hours.

    Args:
        max_age_hours: Maximum age of cache in hours before updating (default: 24)
        verbose: Print status messages (default: True)

    Returns:
        bool: True if update was performed, False if cache was fresh
    """
    registry = VatRuleRegistry()

    # Check if cache file exists
    if not os.path.exists(registry.cache.filename):
        if verbose:
            print(f'VAT cache file does not exist, updating from EU database...')
        registry.update()
        if verbose:
            print(f'✓ VAT data updated successfully')
        return True

    # Check cache age
    cache_age_seconds = time.time() - registry.cache_last_update
    cache_age_hours = cache_age_seconds / 3600

    if cache_age_hours > max_age_hours:
        if verbose:
            last_update = datetime.fromtimestamp(registry.cache_last_update)
            print(f'VAT cache is {cache_age_hours:.1f} hours old (last updated: {last_update})')
            print(f'Threshold: {max_age_hours} hours. Updating from EU database...')
        registry.update()
        if verbose:
            print(f'✓ VAT data updated successfully')
        return True
    else:
        if verbose:
            last_update = datetime.fromtimestamp(registry.cache_last_update)
            print(f'VAT cache is fresh ({cache_age_hours:.1f} hours old, last updated: {last_update})')
        return False


def get_vat_rate_with_auto_update(country_code, max_cache_age_hours=24):
    """
    Get VAT rate for a country, automatically updating cache if needed.

    Args:
        country_code: ISO 3166-1 alpha-2 country code (e.g., 'EE', 'CZ')
        max_cache_age_hours: Maximum cache age before auto-update (default: 24)

    Returns:
        VatRate object with rate, reduced flag, description, etc.
    """
    update_vat_data_if_needed(max_age_hours=max_cache_age_hours, verbose=False)
    return eurovat.get_vat_rate(country_code)