Add support for devcontainers

[adamruzicka]

It would be nice if this could get us to a state where those using vscode (or any of the other devcontainer-related tooling) could just open the repo, let the tooling crunch for a bit and then be able to do all the packaging actions without having to fiddle with anything.

TODOs:

• Add obal, mock and friends. In general get this to a feature parity with what you get when you run the rpm_packaging role from forklift
• some comments about how to make this work with podman instead of docker

[ekohl]

TODOs:

* [ ]  Add obal, mock and friends. In general get this to a feature parity with what you get when you run the [rpm_packaging role](https://github.com/theforeman/forklift/blob/master/roles/rpm_packaging/tasks/main.yml) from forklift

I have https://copr.fedorainfracloud.org/coprs/ekohl/obal/ and think I could publish for EL as well. I used to do that for EL7 but never added EL 8 or 9. Would that make it easier?

Though I see the last tag was over a year ago so we should probably create a new release again.

[adamruzicka]

We already have the how and the necessary dependencies captured in forklift, but having a copr repo would still make it a little bit easier, although it is not strictly necessary.

[ekohl]

I have some vague recollection that GH would also recognize these for codespaces and when Vox Pupuli had a credit card attached to it that would bill. Not that we have one now for Foreman, but I still think we should evaluate https://docs.github.com/en/codespaces/managing-codespaces-for-your-organization/choosing-who-owns-and-pays-for-codespaces-in-your-organization just to be sure.

[ekohl]

Surprisingly this isn't in EPEL according to https://src.fedoraproject.org/rpms/rubygem-gem2rpm.

[ekohl]

Also surprises me rpmspectool isn't in EPEL (https://src.fedoraproject.org/rpms/rpmspectool). Almost makes me think people typically use Fedora to develop ;)

[adamruzicka]

Alright, this should be more or less ready to go

I have some vague recollection that GH would also recognize these for codespaces

I've heard of that, but have no experience with it and no idea how it works, what the permission model is and who it gets billed to. So yes, definitely something to look into.