fix: compiler warning -Wdelete-incomplete

Not including the header may lead to undefinded behaviour.

Author: freeware-superman

src/libcadet/model/UnitOperationBase.cpp

@@ -12,6 +12,7 @@
 
 #include "model/UnitOperationBase.hpp"
 #include "model/BindingModel.hpp"
+#include "model/ExchangeModel.hpp"
 #include "model/ReactionModel.hpp"
 #include "SimulationTypes.hpp"