migrate every factory query off BuildingSystem onto the free functions

src/balancing/ArenaView.cpp

@@ -1,4 +1,5 @@
 #include "ArenaView.h"
+#include "FactoryQueries.h"
 
 #include <algorithm>
 #include <cmath>
@@ -306,7 +307,7 @@ void ArenaView::drawTiles(QPainter& painter)
 
 void ArenaView::drawBuildings(QPainter& painter)
 {
-    for (const Building& b : m_sim->getBuildings().getAllBuildings())
+    for (const Building& b : getAllBuildings(m_sim->getFactoryState()))
     {
         const std::map<BuildingType, BuildingVisuals>::const_iterator it =
             m_visuals->buildings.find(b.type);