Add a new 2021 roadmap item for Puppet

Working on and improving our Puppet environment while following best practices is currently blocking on our lack of an external node classifier, or ENC. Adding this item as a priority on our roadmap will resolve team#40358 (closed) and help advance team#29387

Deploying hiera-enc in itself should be fairly straightforward, however since some nodes are assigned multiple roles, some of those roles (eg. roles::fde) will have to be converted into profiles instead and included from the role class. So a small amount of restructuring of our roles manifests and current hiera data is to be expected.

If I can focus on this I don't expect it should take more than one week's time (20h) to implement this fully.