Warn user for abnormal temperature differences for nozzle and bed (first layer vs other layers) (#12345)

Warn for first and other layers big temperature delta

Warn user if temperature differences (first layer vs other layers) for nozzle and plates are above a certain delta.

Co-authored-by: SoftFever <softfeverever@gmail.com>

src/slic3r/GUI/Tab.hpp

@@ -419,6 +419,7 @@ public:
 
 	static bool validate_custom_gcode(const wxString& title, const std::string& gcode);
 	bool        validate_custom_gcodes();
+	bool        validate_filament_temperature_pairs();
     bool        validate_custom_gcodes_was_shown{ false };
     void        set_just_edit(bool just_edit);