Port SymbologyImpl Esri processors to the ArcGIS 300 QFuture async API

TaskWatcher (searchSymbols/fetchSymbol/createSwatch + completion signals) -> QFuture (searchSymbolsAsync/fetchSymbolAsync/createSwatchAsync + QFutureWatcher finished/result getter); flat arcgis/ includes; arcgisversion.h shim (external SDK). advancedSymbology now builds+links vs 300 (0 errors); SymbologyXML CTest 6/6, 0 assertion failures. Migration-only vs legacy; one documented forced delta: 300 has no spec-only DictionarySymbolStyle. Summary: MIGRATION_SUMMARY_ARCGIS300_SYMBOLOGY.md.

qt6-after/qt6-migrated-legatus/Lts/Viewer/SituationMap/Map/situation_map_utils.cpp

@@ -12,13 +12,13 @@
 
 
 // Esri
-#include <arcgis/CoreTypes.h> // for LicenseStatus
-#include <arcgis/MapTypes.h>
-#include <arcgis/Viewpoint.h>
-#include <arcgis/Camera.h>
+#include <CoreTypes.h> // for LicenseStatus
+#include <MapTypes.h>
+#include <Viewpoint.h>
+#include <Camera.h>
 
 
-#include <arcgis/arcgisversion.h>  // This file is created by RME, not ESRI
+#include <arcgisversion.h>  // This file is created by RME, not ESRI
 
 #if ACRGIS_VERSION >= 0x640600 // 100.6.0 / Update 6
 #define HAS_SURFACEPLACEMENT_RELATIVETOSCENE