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.

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/