/style and /styles_batch_update require full "A1:A1" form and reject
single-cell shorthand "A1". +set-style was using normalizeSheetRange
(prefix-only) and +batch-set-style passed --data through unchanged,
so both failed with `wrong range` when callers supplied a single cell.
Switch +set-style to normalizePointRange, and walk each ranges[]
entry in +batch-set-style through normalizePointRange before sending.
Multi-cell spans pass through unchanged.