Cache mice & loot lists for slash commands

[bradp]

We should either hardcore or cache a list of mice & items to avoid having to do a call to grab them.

[AardWolf]

I prefer the dynamic aspect. If anything a permissioned command to re-fetch would be an improvement over the current timer method which is occasionally breaking and not setting a new timer.

The refresh time should be increased greatly, maybe to something like 97 minutes or 6 hours. New mice, loot, convertibles aren't added that often and minlucks don't get updated that often.