Adds initial intermediate qt6 porting state

qt6-after/qt6-migrated-legatus/Lts/Plugins/BuildingViewer/Common/bdv_helper.cpp

@@ -0,0 +1,28 @@
+
+
+
+#include "bdv_helper.h"
+
+namespace BuildingViewer
+{
+QString gStrFeatureIdPrefix = QStringLiteral("House_");
+
+
+
+QString databaseId2FeatureId(int32_t buildingDatabaseId)
+{
+  if (buildingDatabaseId <= 0)
+      return QString();
+  return gStrFeatureIdPrefix + QString::number(buildingDatabaseId);
+}
+
+
+int32_t featureId2DatabaseId(const QString &strFeatureId)
+{
+  if (!strFeatureId.startsWith(gStrFeatureIdPrefix))
+    return -1;
+  bool isOk = false;
+  int32_t buildingDatabaseId = strFeatureId.midRef(gStrFeatureIdPrefix.size()).toInt(&isOk);
+  return isOk ? buildingDatabaseId : -1;
+}
+}