Easier way to change the currency name

[srnyx]

Right now, it's pretty annoying having to change all Mystery Dust's to Token's in the different messages files.
Replacing isn't much of an option as the messages settings have Mystery Dust in their name.

I'm proposing a config option like currency-name or something that defaults to mystery dust.
It would be used in messages.yml like this: {CURRENCY-NAME} or something similar.