GUI: serialization refactoring part 7

The the rest of classes have got readFrom and writeTo methods.

Serialization of instruments is done.

The rest of work is to remove all usages and mentions of serialization.

GUI/Model/Device/SpecularBeamInclinationItem.h

@@ -28,8 +28,8 @@ public:
     explicit SpecularBeamInclinationItem(const InstrumentItem* owningInstrument);
 
     void serialize(Streamer& s) override;
-    void writeTo(QXmlStreamWriter* w) const;
-    void readFrom(QXmlStreamReader* r);
+    void writeTo(QXmlStreamWriter* w) const override;
+    void readFrom(QXmlStreamReader* r) override;
 
     double scaleFactor() const override;