For CORGI, we should be able to package Corp/Org resources. Generally, third-party applications can already define third-party resource maps, should be able to package third-party resources as well.

It gets tricky if we're trying to bundle them into first-party packages, or, say, bundle several small extension packages into a single package-of-packages, but we don't need to deal with that for now.

It's possible that this already works and I just forgot how it works, in which case I just need to remember how it works. But I think I didn't implement it since we didn't have much need for it at the time.