UUID Update

Internals were converted to UUIDs, in preparation for Minecraft Name Changing. 
https://forums.bukkit.org/threads/psa-the-switch-to-uuids-potential-plugin-server-breakage.250915/


Important to note that to have a player converted to the new internals, they must log on. 
Once this version is installed, the only thing the old players.db will used for is transferring when they log on. 


RankSuite requires an update to UUIDs so that one cannot lose their playing time because they changed their username. 

This is a re-submitted PR, I simply went back through and patched it for UUIDs instead of fully testing it with the last PR. This code should be ready for production servers, however additional testing may be required to patch small bugs.