Fixed bug where could not load savegame with ImmutableFacts from Solution / ExposedFacts

...ts/Scripts/InteractionEngine/FactHandling/FactComparer.cs

...s/Scripts/InteractionEngine/FactHandling/FactOrganizer.cs

Assets/Scripts/InteractionEngine/FactHandling/FactSpawner.cs

...InteractionEngine/FactHandling/Facts/AbstractAngleFact.cs

.../InteractionEngine/FactHandling/Facts/AbstractLineFact.cs

Assets/Scripts/InteractionEngine/FactHandling/Facts/Fact.cs

...ipts/InteractionEngine/FactHandling/Facts/FunctionFact.cs

Assets/Scripts/InteractionEngine/Gadgets/Gadget.cs

Assets/Scripts/InventoryStuff/ScrollDetails.cs

Assets/Scripts/Loading/Stage.cs

Assets/Scripts/UI/FactExplorer/FactExplorer.cs