[FEATURE] Change customname from offline players

[liamthexpl0rer]

I want an option to change the Prefix/Suffix/Nickname from offline players. Maybe it can be solved via an file in the config folder?

[eclipseisoffline]

Hey! It's been a while. I'll try to work on this when I update the mod to 1.21.5. The feature will then be available for the 1.21.5 and 1.21/1.21.1 versions.