get: allow downloading regular files/dirs tracked by Git

[jorgeorpinel]

As we decide how to list data artifacts in external DVC repos in #2509 it became apparent listing regular files along with stage outputs could be especially useful. See #2509 (comment).

This made us think also then users could want to get some of those individual regular files after seeing them. (See #2509 (comment))

[jorgeorpinel]

Cc @shcheklein

Why dvc get and not dvc import though? What about directory/recursive support for this feature?

Thanks

[efiop]

Related to #2507

Is there an agreement on this one, @efiop ?

[efiop]

@MrOutis Most likely, this will be automatically fixed along the way with #2507

[jorgeorpinel]

...this will be automatically fixed along the way with #2507

Per #2566 (comment), that does not seem to be the case after all, guys.

[efiop]

@jorgeorpinel hence the "most likely" part. As you can see, that PR doesn't have "Fixes" message for this issue. Thanks for the heads up, though.

[jorgeorpinel]

Just keeping track of updates and validity of my issues.