message: Deserialize request into serde Value to avoid loosing of fields
diff: @@ -15,7 +15,6 @@ use domain::crypto::key::Key;
  use domain::ledger::node::NodeOperationData;
  use domain::ledger::author_agreement::{GetTxnAuthorAgreementData, AcceptanceMechanisms};
  use domain::ledger::auth_rule::AuthRules;
  -use domain::ledger::request::Request;
  use errors::prelude::*;
  use services::crypto::CryptoService;
  use services::ledger::LedgerService;
  @@ -1162,10 +1161,10 @@ impl LedgerCommandExecutor {
  debug!("append_txn_author_agreement_acceptance_to_request >>> request_json: {:?}, text: {:?}, version: {:?}, taa_digest: {:?}, acc_mech_type: {:?}, time: {:?}",
  request_json, text, version, taa_digest, acc_mech_type, time);
  - let mut request: Request<serde_json::Value> = serde_json::from_str(request_json)
  + let mut request: serde_json::Value = serde_json::from_str(request_json)
  .map_err(|err| IndyError::from_msg(IndyErrorKind::InvalidStructure, format!("Cannot deserialize request: {:?}", err)))?;
  - request.taa_acceptance = Some(self.ledger_service.prepare_acceptance_data(text, version, taa_digest, acc_mech_type, time)?);
  + request["taa_acceptance"] = json!(Some(self.ledger_service.prepare_acceptance_data(text, version, taa_digest, acc_mech_type, time)?));
  let res: String = serde_json::to_string(&request)
  .to_indy(IndyErrorKind::InvalidState, "Can't serialize request after adding author agreement acceptance data")?;
  @@ -1182,10 +1181,10 @@ impl LedgerCommandExecutor {
  self.crypto_service.validate_did(endorser_did)?;
  - let mut request: Request<serde_json::Value> = serde_json::from_str(request_json)
  + let mut request: serde_json::Value = serde_json::from_str(request_json)
  .map_err(|err| IndyError::from_msg(IndyErrorKind::InvalidStructure, format!("Cannot deserialize request: {:?}", err)))?;
  - request.endorser = Some(endorser_did.to_string());
  + request["endorser"] = json!(endorser_did);
  let res: String = serde_json::to_string(&request)
  .to_indy(IndyErrorKind::InvalidState, "Can't serialize request after adding endorser")?;
  