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.

This patch deployes the fixed postfix image containg postscreen with
enabled smtpd.

This patch creates a PDB for postfix, if the setup is scaled to more
than 1 postfix replica. This way at least one postfix instance should
always be available and the MTA therefore HA.

Currently the dovecot backend is not yet HA, this should take place
later on.

Currently each update of the application version requires an update of
the snapshot, this is annoying and doesn't help the chart with anything.
Therefore this patch enforces a chart version for all snapshot tests and
also stablizes the config reload hash magic regarding versioning
changes.

Currently postfix reports and error due to the missing service. This
patch fixes the problem by enabling the expected service in master.cf

This patch should enable the postfix setup in MoK to utilise the
proxy-protocol and therefore gather required IP information from
connecting clients.

It's implemented based on some documentation regard the topic and is
useful for reverse-proxy setups e.g. behind haproxy.

References:
https://www.haproxy.com/blog/efficient-smtp-relay-infrastructure-with-postfix-and-load-balancers/

This patch adjust the helm package command to only package the actually
changed chart an not double upload packaged helm charts.

This patch adds the common config reload annotation trick to the MoK
helm chart, which should make sure that new users are picked up
immediately.

References:
https://helm.sh/docs/howto/charts_tips_and_tricks/#automatically-roll-deployments

This patch reduces the image builds to a minimum stable releases should
only be build then the `.release` file changes, while deb builds can run
on any commit.

This patch updates the gitlab-ci config to actually build a postfix
image for non-main branches. Previous copy-paste mistake should be fixed
by this.

Currently the service name for dovecot was hardcoded in the image, which
makes it incompatible with MoK. As a result this patch updates the image
to allow a dynamic overwrite on startup as well as updating MoK to
account for the new functionality.