Add support for interacting with dev containers

[tfoote]

If people put the time in to setup dev containers for repos rocker should be able to invoke them effectively.

https://containers.dev/implementors/spec/

[blooop]

This feature will require rocker to be able to build Dockerfiles. Are there any architectural considerations to adding that capability to rocker?

[tfoote]

Generally yes, rocker already does overlays on base images, so following the same approach might work for the dev containers. Alternatively it might make sense to leverage external capabilities if they exist to build the containers first then run them.