This patch adds `automountServiceAccountToken: false` to various
ServiceAccount objects in order to disable automatic mounting of service
accounts tokens to Pods that never need to use them.

This patch hopefully fixes issues with sending kill signals to subprocesses from the master process of dovecot.

Exmaple error logs:
```
Jan 25 00:27:16 master: Error: service(auth): kill(14, SIGINT) failed: Operation not permitted
Jan 25 00:28:16 master: Error: service(auth): Process 14 is ignoring idle SIGINT
```

This patch moves the dovecot config from the container build to the helm
chart which allows to use templating with values that are configured at
runtime. This should provide more flexibility and standardizes the
dovecot container further.

This patch configures postfix to reject incoming email from its own
domains this is an effort to fight phishing of emails from my own domain
claiming to be from postmaster or alike.

References:
https://superuser.com/questions/964958/make-postfix-reject-incoming-email-spoofed-as-from-my-own-domain

The helm-unittest upstream has switched back to the helm-unittest
organisation again. Therefore switching to a different image. With the
switch a few minor, but breaking changes have been introduced.

- Dropping helm v2 support
- adjustment of indentation
- enforcing jsonpath for selection

Reference:
https://github.com/helm-unittest/helm-unittest

With different traffic policies and alike, the shared loadbalancer
causes more problems than it resolves. The original reason was that both
remote addresses would point to the same address, but this is a
non-issue given it all runs through a remote anyway.

Given that currently a lot of connections look broken and result quite delayed
mail delivery adjusting this interval will hopefully help to keep imap
connections alive and therefore delivering emails in realtime.

Currently for some reason postfix decided to drop all email that are
supposed to be relayed by default. This is obviously unwanted behaviour.
This patch takes the settings from the workaround.org project, applies
them to submission and submissions, which fixes the current issue.

However I still don't fully understand why.

References:
https://workaround.org/ispmail/bullseye/relay-outoing-email-through-postfix/

This patch switches the externalTrafficPolicy to `Local` for the
proxy-protocol enabled services, in order to skip kube-proxy when
connecting, this makes sure that proxy-protocol can actually function
and doesn't hit a node that would need to redirect traffic.

References:
https://metallb.org/usage/#layer2
https://github.com/kubernetes/kubernetes/issues/66607
https://github.com/digitalocean/digitalocean-cloud-controller-manager/pull/206

This patch disables error queries from zenhaus. It requires some more
tinkering down the line, but should accept email for now.

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 allows to set the `HOSTNAME` variable, which should
explicitly set the hostname for the postfix pod and configure it to use
the proper external DNS name.