Zero-dependency lookup of BIC and bank name master data (BLZ/Bankleitzahl/BC/kod banky/bank code directories) for a given IBAN or country-specific bank code. Ships a small bundled offline fallback dataset per country ("Urladung") and can refresh its data lazily and asynchronously from the respective national registry at runtime, persisting the result to a local cache directory. Initial country coverage: Germany (DE), Austria (AT), Switzerland (CH), Czech ...