Allow to choose container manager commands (#8380)

This allow to workaround #8375 by using image_command_tool=crictl
when containerd_registries is used for containerd.

Also changes image_info_command_on_localhost for docker to return digests.

(cherry picked from commit cfd9873b)

The cherry-pick was adapted because nerdctl_extra_flags is not in
the release-2.18 branch (#8339).