Support IFOPT station identifiers in OJP/TRIAS responses

autotests/data/ojp/vvo-location-by-name.json

 [
     {
         "identifier": {
+            "ifopt": "de:14612:28",
             "uic": "de:14612:28"
         },
         "latitude": 51.0399284362793,
@@ -11,6 +12,7 @@
     },
     {
         "identifier": {
+            "ifopt": "de:14612:32",
             "uic": "de:14612:32"
         },
         "latitude": 51.0413703918457,
@@ -21,6 +23,7 @@
     },
     {
         "identifier": {
+            "ifopt": "de:14612:36",
             "uic": "de:14612:36"
         },
         "latitude": 51.038719177246094,

src/lib/backends/openjourneyplannerparser.cpp

@@ -8,6 +8,7 @@
 #include "scopedxmlstreamreader.h"
 
 #include <gtfs/hvt.h>
+#include <ifopt/ifoptutil.h>
 
 #include <KPublicTransport/Journey>
 #include <KPublicTransport/Location>
@@ -102,7 +103,11 @@ Location OpenJourneyPlannerParser::parseLocationInformationLocation(ScopedXmlStr
             auto subR = r.subReader();
             while (subR.readNextSibling()) {
                 if (subR.isElement("StopPlaceRef") || subR.isElement("StopPointRef")) {
-                    loc.setIdentifier(m_identifierType, subR.readElementText());
+                    const auto id = subR.readElementText();
+                    loc.setIdentifier(m_identifierType, id);
+                    if (IfoptUtil::isValid(id)) {
+                        loc.setIdentifier(IfoptUtil::identifierType(), id);
+                    }
                 } else if (subR.isElement("StopPlaceName") || subR.isElement("StopPointName")) {
                     loc.setName(parseTextElement(subR.subReader()));
                 }