Initial podman support

In the same vein as 202be7dee6db "PE: Bundles: add support for rkt bundle type"
we add support for another container type for bundles: podman.

Tested with the following container:
podman container set: test_bundle [docker.io/sdelrio/docker-minimal-nginx]

test_bundle-podman-0 (ocf::heartbeat:podman):        Started nodea
test_bundle-podman-1 (ocf::heartbeat:podman):        Started nodeb
test_bundle-podman-2 (ocf::heartbeat:podman):        Started nodec

Tested a couple of stop/start cycles successfully.
I will play with more complex scenarios as all the pieces start coming
together.