This patch drops the kOS setup entirely, since it has been around for
months now, but seems to be impractical as I still didn't bother to put
it in production. Apparently the usage of Fedora Server with the
existing automatic update mechanisms has proven suffient for now.

Currently the it says `3.6e7` due to either yaml, or flux optimising the
representation of the number. Despite the good intend, this causes
hedgedoc to interpret the session lifetime as 3.6 milliseconds, which
obviously is a bit brief for a HTTP session.

This patch adds the unreleased healthcheck path as well as setting
hedgedoc up for PSS of restricted.

This patch reworks parts of the helm chart, to always include boolean
values with their default instead of using a `with` clause. Since the
`with` clause works like an `if`, it would not explicitly decleare a
`false` value due to evaluating to false and therefore not being
considered for content evaluation.

This patch allows to deploy TLS support for the database backend.