Correctly register argument types with a namespace

[astei]

As per Dinnerbone when namespaces were first introduced:

Please always use your own namespace for anything new that you add, and only use other namespaces if you're explicitly overriding something else. Try not to add new things in minecraft, basically.

Violating this practice causes the mod to not work with Minecraft proxies such as Velocity which can forward custom argument types from mods with the assistance of CrossStitch.

(Note this will require the client and server to be updated to work.)

[OverlordsIII]

Sorry about not using the correct namespace, I will merge this now.