Fix terrain_profile_processor.cpp: add Multipart.h include for ImmutablePart types

- Added #include <Multipart.h> to resolve ImmutablePart and ImmutablePartCollection incomplete type errors
- Required for Qt6/ArcGIS SDK v300 compatibility

qt6-after/qt6-migrated-legatus/Lts/Viewer/SituationMap/MapImpl/terrain_profile_processor.cpp

@@ -21,6 +21,11 @@
 // ESRI
 #include <GeometryEngine.h>
 #include <PolylineBuilder.h>
+#include <Polyline.h>
+#include <Part.h>
+#include <Multipart.h>
+#include <LinearUnit.h>
+#include <AngularUnit.h>
 
 
 // Qt