UK sort code checker

Three separate verdicts, kept separate on purpose. The format check is exact. The bank name is indicative and dated: banks re-allocate prefixes, so treat it as a hint, not a directory. The modulus checks only run on the weighting rows you paste, because valacdos.txt is updated every few weeks and a stale bundled table would hand out confident wrong verdicts; no row, no check. Exception rows (codes 1 to 14) change which digits carry the check and how products fold, so they are reported out of scope rather than checked wrongly. A passing modulus check is not account existence, and it is not a Confirmation of Payee name match.