Reduce string storage, use masking 'seen'

Marlin/src/HAL/HAL_DUE/EepromEmulation.cpp

Marlin/src/Marlin.cpp

Marlin/src/feature/bedlevel/ubl/ubl.cpp

Marlin/src/feature/prusa_MMU2/mmu2.cpp

Marlin/src/gcode/bedlevel/M420.cpp

Marlin/src/gcode/config/M281.cpp

Marlin/src/gcode/config/M301.cpp

Marlin/src/gcode/config/M302.cpp

Marlin/src/gcode/config/M304.cpp

Marlin/src/gcode/config/M92.cpp

Marlin/src/gcode/control/M280.cpp

Marlin/src/gcode/feature/L6470/M906.cpp

Marlin/src/gcode/feature/advance/M900.cpp

Marlin/src/gcode/feature/powerloss/M413.cpp

Marlin/src/gcode/probe/M951.cpp

...extensible_ui/lib/lulzbot/archim2-flash/flash_storage.cpp

...extensible_ui/lib/lulzbot/ftdi_eve_lib/basic/commands.cpp

.../extensible_ui/lib/lulzbot/ftdi_eve_lib/basic/constants.h

...ensible_ui/lib/lulzbot/ftdi_eve_lib/extended/dl_cache.cpp

...sible_ui/lib/lulzbot/ftdi_eve_lib/extended/screen_types.h