Animated Marlin boot screen (#14961)

Marlin/Configuration_adv.h

Marlin/src/lcd/dogm/dogm_Bootscreen.h

Marlin/src/lcd/dogm/dogm_Statusscreen.h

Marlin/src/lcd/dogm/ultralcd_DOGM.cpp

buildroot/share/tests/megaatmega2560-tests

config/default/Configuration_adv.h

config/examples/3DFabXYZ/Migbot/Configuration_adv.h

config/examples/AlephObjects/TAZ4/Configuration_adv.h

config/examples/Alfawise/U20/Configuration_adv.h

config/examples/AliExpress/UM2pExt/Configuration_adv.h

config/examples/Anet/A2/Configuration_adv.h

config/examples/Anet/A2plus/Configuration_adv.h

config/examples/Anet/A6/Configuration_adv.h

config/examples/Anet/A8/Configuration_adv.h

config/examples/Anet/A8plus/Configuration_adv.h

config/examples/Anet/E16/Configuration_adv.h

config/examples/AnimationExample/_Bootscreen.h

config/examples/AnyCubic/i3/Configuration_adv.h

config/examples/ArmEd/Configuration_adv.h

config/examples/BIBO/TouchX/cyclops/Configuration_adv.h