NOTE: This does not include info structs like other settings, because we
(deliberately) provide no interface for creating new mods or admins
except through the command line, ensuring that the host of the
server has total control over these things and avoiding the creation
of code paths to alter the admin list that are accessible during normal
gameplay.
Important: even if the role we are storing here appears to be identical
to one used in another versioned store (like banlist::Role), we
must have our own versioned copy! This ensures that if there’s an
update to the role somewhere else, the conversion function between
them will break, letting people make an intelligent decision.