`TransactionEvent` can be `FormatViolation` without `triggerReason`

[KSR-Yasuda]

In some cases, TransactionEvent do not have the required property triggerReason.

In TransactionService::Evse::loop(),
here it sets event triggerReason, but it may be the initial value UNDEFINED.

Then, the triggerReason property is skipped in message serialization.

Shouldn't you set something to follow the OCPP spec?

[KSR-Yasuda]

Perhaps here is where to set txEvent->transaction->stopTrigger.

If the started transaction comes to be active = false,
it would fall into the case of TransactionEventData::Type::Ended above.

--- a/src/MicroOcpp/Operations/TransactionEvent.cpp
+++ b/src/MicroOcpp/Operations/TransactionEvent.cpp
@@ -131,14 +131,23 @@ std::unique_ptr<JsonDoc> TransactionEvent::createReq() {
 void TransactionEvent::processConf(JsonObject payload) {
 
     if (payload.containsKey("idTokenInfo")) {
         if (strcmp(payload["idTokenInfo"]["status"], "Accepted")) {
             MO_DBG_INFO("transaction deAuthorized");
             txEvent->transaction->active = false;
             txEvent->transaction->isDeauthorized = true;
+            if (txEvent->transaction->started && !txEvent->transaction->stopped) {
+                if (txEvent->transaction->stopTrigger == TransactionEventTriggerReason::UNDEFINED) {
+                    txEvent->transaction->stopTrigger = TransactionEventTriggerReason::Deauthorized;
+                }
+
+                if (txEvent->transaction->stoppedReason == Ocpp201::Transaction::StoppedReason::UNDEFINED) {
+                    txEvent->transaction->stoppedReason = Ocpp201::Transaction::StoppedReason::DeAuthorized;
+                }
+            }
         }
     }
 }
 
 void TransactionEvent::processReq(JsonObject payload) {
     /**
      * Ignore Contents of this Req-message, because this is for debug purposes only