This patch configures the longhorn backup storage for longhorn. It's a
first run until the proper backup storage is complete.

This patch renames all uses of `Containerfile` with `Dockerfile` in
order to enable renovate to manage dependencies and images properly.
Currently renovate doesn't support the Containerfile name as match for
its docker module, which would mean that either there is custom config
added or renaming the files. Since there is no explicit benefit of using
Containerfile as name, this patch just renames them in order to avoid
custom renovate config.

Turns out there are unexpected structural changes in this upgrade that
we need to address separately.

It requires to deploy a CR after successful deployment, which means
we'll have to move the helm chart to bootstrape of work around this in
another way.

This patch adds the missing capability to install CRDs as part of the
metallb deployement.

This patch removes the component label, which was previously manually
added by our deployment, but is now part of the helm chart.

Due to a copy-paste mistake, dovecot was using the postfix replicaCount
for its own. This is obviously not intended and was fixed by this
commit, correcting the snapshot and adding obviously needed tests to
prevent such a mistake in the future.