Reverse BIC / SWIFT code lookup: given a BIC, return the resolved bank name(s), the country and the domestic bank codes.

Reverse BIC / SWIFT code lookup: given a BIC, return the resolved bank name(s), the country and the domestic bank codes. Offline open-registry data (schwifty, MIT); no network or keys. A malformed BIC returns valid false with an error_type, never a 500.