[Feature Request] Add config option to ignore unknown application commands

[CodedSakura]

If i use the same bot client with a different instance while the server is offline, and i want that to have it's own application commands, i can't, since BlockBot will remove them. (ik running multiple instances on the same bot is not good practice, but i don't want to clutter the discord server with bots :P )

A whitelist option for unknown commands could also do the trick.