ENH: refresh nozzle info from studio

Jira: [STUDIO-13650]
Change-Id: I12dc26d5730c761ccc91d3a4a5f120d422d8a0ff
(cherry picked from commit 2bd7cd9a6a4d9c3370491fb4323a1aabe9a45578)

src/slic3r/GUI/DeviceCore/DevNozzleSystem.h

@@ -28,6 +28,7 @@ namespace Slic3r
        bool                            ContainsNozzle(int id) const { return m_nozzles.find(id) != m_nozzles.end(); }
        DevNozzle                       GetNozzle(int id) const;
        const std::map<int, DevNozzle>& GetNozzles() const { return m_nozzles;}
+       bool                            IsRefreshing() const { return m_state == 1; }
 
    private:
        void Reset();