Added error cases for storage services and optimized azure getFile

Editor assessment

Two changes share one subject, added error cases for storage services and an optimization of the azure getFile path, which blurs the unit of work. 'Added' is capitalized past tense, and no scope marks storage. No body explains what errors can now occur, how the Azure path was optimized, or what the measured improvement was, so the reader must open the diff for anything concrete. Feat is a defensible type for new error handling. Hygiene otherwise passable. Understandable, honest, and thin, with the mixed concerns doing the message no favors.