Bundle Registering

[cart]

It should be possible to register Bundles the same way we currently register components. This would enable a number of things:

• app.register_bundle<MyBundle>() would be a nice shorthand for registering all components in the bundle
• It would allow us to use bundles in the scene system
• It would allow the editor to be aware of bundles / use them during scene construction

[alice-i-cecile]

#4154 proposes an alternate strategy for type registration.

#4072 discusses the levels of abstraction, and whether or not bundles are the right tool for the job.

[james7132]

This was added in a public facing way in #12573. Misread the issue, whoops.