New flags in Podman v4

[theEndBeta]

Are there guidelines on how to add support for flags that are only available as of Podman 4.0? Specifically, I would like to add support for the --wants and --after flags of podman generate systemd. I've made the changes in a fork, but none of the tests are set up for v4 yet, and I don't see them able to be included in default ansible for a while given Ubuntu 22.04 is shipping with v3.4.

[sshnaidm]

Done in #431