pub fn fn_key_share_extension_append(
key_shares: &Vec<KeyShareEntry>,
key_share_entry: &KeyShareEntry,
) -> Result<Vec<KeyShareEntry>, FnError>pub fn fn_key_share_extension_append(
key_shares: &Vec<KeyShareEntry>,
key_share_entry: &KeyShareEntry,
) -> Result<Vec<KeyShareEntry>, FnError>