Consider splitting up pkg/util into semantically-relevant subpackages

[mtrmac]

See https://github.com/containers/skopeo/pull/2112/files : adding a call to util.ReadPassword triggers addition of several other unnecessary subpackages. (I am starting to think that a util subpackage is always a mistake because it will become a dependency magnet like this, caller of one small thing accrues several other unwanted dependencies.)

This is, of course, quite low-priority.

[rhatdan]

I agree lets break this into a series of subpackages.

[vrothberg]

I am also supportive. Some files in Podman import 3 or more "util" or "utils" packages.

[mtrmac]

Thanks @rhatdan .