Rework provisioning of container integration jars

[rhusar]

Currently a version must be in sync with mod_cluster repo, so every time mod_cluster moves to next release, this breaks and needs an update.

The advantage is that we can test and detect problems early but this should rarely be necessary to need to rely on snapshot version.

We should decide whether:

• remove poms + download released distribution zips from maven + unzip
• update mod_cluster to deploy snapshot from main and same as above but download snapshot distribution zips from maven
• keep relying on maven based distribution from pom but for release version

[jajik]

What about removing poms, but instead of downloading released distribution, we would use mod_cluster repository as a submodule?

That would enable multiple things:

• we could drop the "have the repo checked out" requirement
• it would allow us easily switch between versions we use (by default HEAD, but we might as well check out just a different version – it's just a git)
• I forgot the third one I had in mind 🙂