Function batch_conversion_errors 

#[doc(hidden)]
pub fn batch_conversion_errors(
    container: &str,
    errors: Vec<String>,
) -> SexpError

Combine indexed per-element conversion failures into one batched SexpError::InvalidValue.

Backs the Vec<T> / Vec<Option<T>> arms of [try_from_sexp_via_str_parse!]: instead of bailing on the first NA or parse failure, those arms walk the whole vector, accumulate the already-formatted per-element messages, and hand them here. Entries are joined with "; "; at most the first 10 are listed and the remainder is summarized as "and N more".

Public (but hidden) because try_from_sexp_via_str_parse! is #[macro_export] and expands in downstream crates — not intended to be called directly.