Function normalize_fixed_len_byte_array_payload 

pub(crate) fn normalize_fixed_len_byte_array_payload(
    data: Bytes,
    num_values: usize,
    type_length: usize,
    page: &str,
) -> Result<Bytes>

Validate a complete decompressed PLAIN FLBA value section, excluding levels. num_values must count physical non-null values, not rows or requested values. Canonical payloads are returned unchanged, even if values resemble prefixes.