Update French language (#14787)

Marlin/src/lcd/language/language_fr.h

 #define MSG_UBL_LEVEL_BED                   _UxGT("Niveau lit unifié")
 #define MSG_LCD_PROBING_MESH                _UxGT("Mesure point")
 #define MSG_LCD_TILTING_MESH                _UxGT("Touche point")
+#define MSG_M48_TEST                        _UxGT("Ecart sonde Z M48")
+#define MSG_M48_DEVIATION                   _UxGT("Ecart")
 #define MSG_IDEX_MENU                       _UxGT("Mode IDEX")
 #define MSG_IDEX_MODE_AUTOPARK              _UxGT("Auto-Park")
 #define MSG_IDEX_MODE_DUPLICATE             _UxGT("Duplication")
 #define MSG_SINGLENOZZLE_RETRACT_SPD        _UxGT("Vitesse retrait")
 #define MSG_NOZZLE_STANDBY                  _UxGT("Attente buse")
 #define MSG_FILAMENT_SWAP_LENGTH            _UxGT("Distance retrait")
+#define MSG_FILAMENT_PURGE_LENGTH           _UxGT("Longueur de purge")
 #define MSG_FILAMENTCHANGE                  _UxGT("Changer filament")
 #define MSG_FILAMENTLOAD                    _UxGT("Charger filament")
 #define MSG_FILAMENTUNLOAD                  _UxGT("Retrait filament")
 #define MSG_VTOOLS_RESET                    _UxGT("V-tools réinit. ok")
 #define MSG_START_Z                         _UxGT("Début Z")
 #define MSG_END_Z                           _UxGT("  Fin Z")
+#define MSG_GAMES                           _UxGT("Jeux")
 #define MSG_BRICKOUT                        _UxGT("Casse-briques")
 #define MSG_INVADERS                        _UxGT("Invaders")
 #define MSG_SNAKE                           _UxGT("Sn4k3")