Move Azure scripts to infra directory, as only roles and modules test
playbooks should exist in the tests directory.

CentOS 7 containers are not working in recent versions of systemd.

The upstream CI tests can be simplified by using the script
infra/image/start.sh to start the testing container and using a steps
template playbook to prepare the environment.

Although not required, the environment and test template separation
aid on the future modification of the pipelines.

On Github and Azure, Ubuntu 22.04 images do not allow the selection of
the CPU numbers.

For some time now, we had some issues with molecule when building test
images for ansible-freeipa, and replaced the image creation with custom
build scripts that use commom container tools (like Dockerfiles and the
build command).

As there's no more tasks that require the use of molecule, this patch
removes the last bits used by it, and fixes documentation and lint
scripts and configuration.