message: Init implementation of GET_TXN state proof parsing
diff: @@ -371,6 +371,8 @@ fn _parse_reply_for_sp(json_msg: &SJsonValue, data: Option<&str>, parsed_data: &
  let proof = if let Some(proof) = json_msg["state_proof"]["proof_nodes"].as_str() {
  trace!("TransactionHandler::parse_reply_for_builtin_sp: proof: {:?}", proof);
  proof
  + } else if xtype == constants::GET_TXN && json_msg["audit_path"].as_vec().is_some() {
  +
  } else {
  return Err("No proof".to_string());
  };
  @@ -378,6 +380,8 @@ fn _parse_reply_for_sp(json_msg: &SJsonValue, data: Option<&str>, parsed_data: &
  let root_hash = if let Some(root_hash) = json_msg["state_proof"]["root_hash"].as_str() {
  trace!("TransactionHandler::parse_reply_for_builtin_sp: root_hash: {:?}", root_hash);
  root_hash
  + } else if xtype == constants::GET_TXN && json_msg["root_hash"].as_str().is_some() {
  + json_msg["root_hash"].ok_or()
  } else {
  return Err("No root hash".to_string());
  };
  