docker2podman: manage dashboard nodes

docker2podman: manage dashboard nodes

The dashboard nodes (alertmanager, grafana, node-exporter, and prometheus)
were not manage during the docker to podman migration.

This adds the systemd container template of those services to a dedicated
file (systemd.yml) in order to include it in the docker2podman playbook.

This also adds the dashboard container images pull from docker to podman.

Closes: https://bugzilla.redhat.com/show_bug.cgi?id=1829389
Signed-off-by: Dimitri Savineau <dsavinea@redhat.com>
(cherry picked from commit 252e78b4e4e90bc1c21d9dfd4a7c9bd132e94730)