sysutils/podman: new port

podman (Pod Manager) is a fully featured container engine that is a simple
daemonless tool.  podman provides a Docker-CLI comparable command line
that eases the transition from other container engines and allows the
management of pods, containers and images.  Simply put: alias docker=podman.

podman uses Buildah(1) internally to create container images.  Both tools
share image (not container) storage, hence each can use or manipulate
images (but not containers) created by the other.

PR:		267184
Reviewed by:	arrowd
Reviewed by:	dch
Sponsored by:	SkunkWerks, GmbH
Differential Revision:	https://reviews.freebsd.org/D37324