Component registration API

[keianhzo]

No description provided.

[Exairnous]

Unregistering components from other add-ons can cause a crash because the component can end up getting unregistered twice (once by the other add-on and once by the Hubs add-on). We would like to support other add-ons registering components, so this should be fixed (likely by adding in an option (default true) to add/remove the component from the registry on register/unregister) and the registration api should be documented.