This simply provides the base API to create the objects. Further commits will come that adds
adds usage of this API to existing GameProfile based API's, as well as new API's.
Any plugin still using this API will result in the server saving an inconsistent UUID to player data files,
which then triggers warnings such as "Tried to load unrecognized recipe: bukkit:9e5b92f5-e549-4f47-b0a8-9f89390ed77b removed now."
on the players login.
Plugin authors need to define a key to keep it consistent between server restarts.