Implementation of the localize_validate tool.

Kind-aware validator. Given a kind (currency, calendar, territory, script, number_system, language, locale) and a binary or atom value, returns a structured record showing whether Localize accepts the input and what canonical atom (if any) it resolves to.

Backed by the existing Localize.X.validate_* accessors. Thin facade — the value is the consistent output shape across kinds.