Added missing translations (#6458)

Marlin/language_it.h

 #define DISPLAY_CHARSET_ISO10646_1
 
 #define WELCOME_MSG                         MACHINE_NAME _UxGT(" pronto.")
+#define MSG_BACK                            _UxGT("Indietro")
 #define MSG_SD_INSERTED                     _UxGT("SD Card inserita")
 #define MSG_SD_REMOVED                      _UxGT("SD Card rimossa")
 #define MSG_LCD_ENDSTOPS                    _UxGT("Endstop")
 #define MSG_MAIN                            _UxGT("Menu principale")
 #define MSG_AUTOSTART                       _UxGT("Autostart")
 #define MSG_DISABLE_STEPPERS                _UxGT("Disabilita Motori")
+#define MSG_DEBUG_MENU                      _UxGT("Menu di debug")
+#define MSG_PROGRESS_BAR_TEST               _UxGT("Test barra avanzamento")
 #define MSG_AUTO_HOME                       _UxGT("Auto Home")
 #define MSG_AUTO_HOME_X                     _UxGT("Home asse X")
 #define MSG_AUTO_HOME_Y                     _UxGT("Home asse Y")
 #define MSG_PREHEAT_1                       _UxGT("Preriscalda PLA")
 #define MSG_PREHEAT_1_N                     MSG_PREHEAT_1 _UxGT(" ")
 #define MSG_PREHEAT_1_ALL                   MSG_PREHEAT_1 _UxGT(" Tutto")
+#define MSG_PREHEAT_1_END                   MSG_PREHEAT_1 _UxGT(" Fine")
 #define MSG_PREHEAT_1_BEDONLY               MSG_PREHEAT_1 _UxGT(" Piatto")
 #define MSG_PREHEAT_1_SETTINGS              MSG_PREHEAT_1 _UxGT(" conf")
 #define MSG_PREHEAT_2                       _UxGT("Preriscalda ABS")
 #define MSG_PREHEAT_2_N                     MSG_PREHEAT_2 _UxGT(" ")
 #define MSG_PREHEAT_2_ALL                   MSG_PREHEAT_2 _UxGT(" Tutto")
+#define MSG_PREHEAT_2_END                   MSG_PREHEAT_2 _UxGT(" Fine")
 #define MSG_PREHEAT_2_BEDONLY               MSG_PREHEAT_2 _UxGT(" Piatto")
 #define MSG_PREHEAT_2_SETTINGS              MSG_PREHEAT_2 _UxGT(" conf")
 #define MSG_COOLDOWN                        _UxGT("Raffredda")
 #define MSG_RETRACT                         _UxGT("Ritrai")
 #define MSG_MOVE_AXIS                       _UxGT("Muovi Asse")
 #define MSG_LEVEL_BED                       _UxGT("Livella piano")
+#define MSG_MOVING                          _UxGT("In movimento...")
+#define MSG_FREE_XY                         _UxGT("XY liberi")
 #define MSG_MOVE_X                          _UxGT("Muovi X")
 #define MSG_MOVE_Y                          _UxGT("Muovi Y")
 #define MSG_MOVE_Z                          _UxGT("Muovi Z")
 #define MSG_FILAMENT                        _UxGT("Filamento")
 #define MSG_VOLUMETRIC_ENABLED              _UxGT("E in mm3")
 #define MSG_FILAMENT_DIAM                   _UxGT("Diam. filo")
+#define MSG_ADVANCE_K                       _UxGT("K avanzato")
 #define MSG_CONTRAST                        _UxGT("Contrasto LCD")
 #define MSG_STORE_EEPROM                    _UxGT("Salva in memoria")
 #define MSG_LOAD_EEPROM                     _UxGT("Carica da memoria")
 #define MSG_DELTA_CALIBRATE_Y               _UxGT("Calibra Y")
 #define MSG_DELTA_CALIBRATE_Z               _UxGT("Calibra Z")
 #define MSG_DELTA_CALIBRATE_CENTER          _UxGT("Calibra Center")
+#define MSG_DELTA_AUTO_CALIBRATE            _UxGT("Auto calibrazione")
+#define MSG_DELTA_HEIGHT_CALIBRATE          _UxGT("Imp. altezza Delta")
 #define MSG_INFO_MENU                       _UxGT("Riguardo stampante")
 #define MSG_INFO_PRINTER_MENU               _UxGT("Info. stampante")
 #define MSG_INFO_STATS_MENU                 _UxGT("Statistiche")
 #define MSG_FILAMENT_CHANGE_OPTION_HEADER   _UxGT("CAMBIA OPZIONI:")
 #define MSG_FILAMENT_CHANGE_OPTION_EXTRUDE  _UxGT("Estrusione")
 #define MSG_FILAMENT_CHANGE_OPTION_RESUME   _UxGT("Riprendi stampa")
+#if ENABLED(DOGLCD)
+  #define MSG_FILAMENT_CHANGE_MINTEMP         _UxGT("Temp minima è ")
+#else
+  #define MSG_FILAMENT_CHANGE_MINTEMP         _UxGT("Temp minima e ")
+#endif
+#define MSG_FILAMENT_CHANGE_NOZZLE          _UxGT("  Ugello: ")
 
 #if LCD_HEIGHT >= 4
   // Up to 3 lines allowed
   #define MSG_FILAMENT_CHANGE_INSERT_1        _UxGT("Inserisci il")
   #define MSG_FILAMENT_CHANGE_INSERT_2        _UxGT("filamento e")
   #define MSG_FILAMENT_CHANGE_INSERT_3        _UxGT("premi per cont")
+  #define MSG_FILAMENT_CHANGE_HEAT_1          _UxGT("Premi per")
+  #define MSG_FILAMENT_CHANGE_HEAT_2          _UxGT("riscald ugello.")
+  #define MSG_FILAMENT_CHANGE_HEATING_1       _UxGT("Riscald. ugello")
+  #define MSG_FILAMENT_CHANGE_HEATING_2       _UxGT("Attendere...")
   #define MSG_FILAMENT_CHANGE_LOAD_1          _UxGT("Attendere")
   #define MSG_FILAMENT_CHANGE_LOAD_2          _UxGT("il caricamento")
   #define MSG_FILAMENT_CHANGE_LOAD_3          _UxGT("del filamento")
   #define MSG_FILAMENT_CHANGE_INIT_1          _UxGT("Attendere...")
   #define MSG_FILAMENT_CHANGE_UNLOAD_1        _UxGT("Espulsione...")
   #define MSG_FILAMENT_CHANGE_INSERT_1        _UxGT("Inserisci e premi")
+  #define MSG_FILAMENT_CHANGE_HEATING_1       _UxGT("Riscaldamento...")
   #define MSG_FILAMENT_CHANGE_LOAD_1          _UxGT("Caricamento...")
   #define MSG_FILAMENT_CHANGE_EXTRUDE_1       _UxGT("Estrusione...")
   #define MSG_FILAMENT_CHANGE_RESUME_1        _UxGT("Ripresa...")