Core/Maps: initialize PositionFullTerrainStatus to avoid having issues with those variables (#22315)

src/server/game/Maps/Map.h

@@ -177,6 +177,7 @@ struct PositionFullTerrainStatus
         uint32 const mogpFlags;
     };
 
+    PositionFullTerrainStatus() : areaId(0), floorZ(0.0f), outdoors(true) { }
     uint32 areaId;
     float floorZ;
     bool outdoors;