volume: Can't we have a uniform interface for normal containers and in-VM containers?

https://github.com/firecracker-microvm/firecracker-containerd/pull/631#pullrequestreview-979369783

> I think this is fine for now, but I'd like to see a follow up (maybe just an issue for now) with a deeper dive on if we could make this more transparent. Could we do it with the abstractions we have today? Is there a way to extend the containerd abstractions to allow this?

Start with the linked pull request review and trace the current volume handling for normal containers and in-VM containers. Read the containerd abstractions referenced there, then determine whether they can expose a uniform interface; done means a concrete design or implementation path is agreed.

Written by the indexing model from the issue text.