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.
Let plugins be able to control tab completion of commands and chat async.
This will be useful for frameworks like ACF so we can define async safe completion handlers,
and avoid going to main for tab completions.
Especially useful if you need to query a database in order to obtain the results for tab
completion, such as offline players.
Also adds isCommand and getLocation to the sync TabCompleteEvent
