some GUI settings not serialized

grep for installIntoGroupBox\( shows that the following sources contain collapsible group boxes for which the collapsed/expanded state is not saved:

• ./GUI/View/Instrument/InstrumentLibraryEditor.cpp
• ./GUI/View/Instrument/OffspecDetectorEditor.cpp
• ./GUI/View/Mask/MaskEditorPropertyPanel.cpp
• ./GUI/View/Project/SimulationView.cpp
• ./GUI/View/Project/ProjectsView.cpp

changed the description

Now I see entry of installIntoGroupBox only in /GUI/View/Instrument/InstrumentLibraryEditor.cpp

assigned to @m.svechnikov

changed the description

mentioned in merge request !2110 (merged)

mentioned in commit a4a6825b

closed with merge request !2110 (merged)