Add nbt base 64 codes to java so we can use custom heads and dummies

I want custom heads and dummies using base 64 codes on all platforms this is usefull for map making and custom heads are an iconic part of Minecraft map making, further more so are dummies. Now one more thing base 64 can help with is allowing us to save skins we draw ourselves to our account so we can play with them on consoles, I am trans and have a skin I made myself that makes me feel comfortable I wanna be able to use that.