This patch re-unifies the build pipelines for images including kOS to use
a central CI definition instead of a specific one for kOS.

This patch provides the first release of kOS, a new Fedora CoreOS remix,
that is focused on the current setup of the SI infrastructure.

It basically implements all the little hacks and adjustments that are
currently active on the (existing) Fedora Server nodes running the
infrastructure and will provide a better replacement as soon as they are
put in production.

This patch reorders CI steps and adjusts some names. It also adjusts the
exists rule, which doesn't seem to trigger as expected.

This patch introduces the CI integration for helm-unittest, a nice helm
plugin, which allows to run automatic tests on helm charts and
validating the YAML based on individual settings with clear reports in
gitlab.

This patch replaces the individual helm chart gitlab-ci yamls with a
common gitlab-ci yaml for all charts, that will trigger based on changes
and allow more generalised and unified CI jobs for all charts.

This patch configures the git-chglog tool to generate the release notes
for newer releases. This is a first step in pushing the tooling around
the repositories further and providing a better overview over the
changes in the repository.

This patch reworks the image build process, to utilise GitLab matrix
build feature to generate all jobs, reducing code duplication.

This patch adds a gitlab-ci integration while tekton is still in the
works. This should build all images required, while keeping the door
open for switching to tekton soon.

This patch introduces calver releases to the repository, this is just to
document progress and helps to navigate the changes in the future.