RFE: support copying files from containers via crictl

Copied from RHBZ 2048746, per request:

This is a request to add support for copying files out of containers managed by cri-o. Similar to docker/podman functionality ala `podman cp $container:$src_path $dest_path.

The primary driver of this request is upcoming increased use of sos (i.e. sosreport) on OCP clusters. sos just recently added support for copying files out of containers to be included in sos report archives which is functional for docker and podman. This is at the end of the day provided via wrappers which properly format a command string for whatever is managing the running containers - docker, podman, crio, etc...

OCP eng recently helped to add cri-o support to sos (insofar as being able to query running containers and format commands to execute inside of those containers and collect the command's output in the sos archive), so the missing functionality here is something akin to `crictl cp`.

I know that in upstream this has previously been deferred to using `kubectl cp`, however exposing this via `crictl` would be beneficial to support and the overall supportability of OCP.

Mimic'ing `podman cp` functionality would be sufficient for this use case.

Wishlist enhancement would be to allow writing to stdout (e.g. `crictl cp $con:/some/file -` to not forcibly write the output as a binary tar archive, and just stream the raw text to stdout.