improve: enhance CV validator error messages with invalid values and valid options#864

Darner Iszat Diaz Zapana (DarnerDiaz) wants to merge 1 commit intoMetOffice:mainMetOffice/CDDS:mainfrom

DarnerDiaz:improve/cv-validator-error-messagesDarnerDiaz/CDDS:improve/cv-validator-error-messagesCopy head branch name to clipboard