Resolves a CAS number or English chemical name to its Wikidata label and aliases in
another language. Cached for wikidata.ttlDays (config.json); a definitive "no match"
is cached as an empty array, a failed request (undefined) is not.
Resolves a chemical name written in English or a configured source language (see
wikidata.sourceLanguages in config.json, e.g. Dutch zoutzuur) to its English name and CAS number. The term must
equal a Wikidata label or alias exactly, so an unrelated top search hit is never trusted.
Cached for wikidata.ttlDays; a definitive "no match" is cached as {}, a failed request
(undefined) is not.
A chemical resolved to its English name and CAS number. Both are absent for "no match".