Adding feature for local-data entries

[AkaBlur]

Hi @DO1JLR,

I've added a feature to this Ansible role which allows the user to configure local-data entries inside
the Unbound configuration.

---

A basic template variable has been added with

# list of optional local-data entries
unbound__local_data: []

This can also be left empty or omitted, the configuration will consider the state of these
variables. They will be only inserted if defined, so idempotency should be preserved.

Configuring the entries can be done via adding the DNS configuration entry into the list:

unbound__local_data: [
  "homeassistant.local A 10.0.0.25",
  "gitea.local A 10.0.0.20"
]

The host will receive an additional local-data.conf inside unbound.conf.d if any entries exist.

---

As of the nature of Unbound no CNAME/DNAME support is generally available (without stub-zones).
However, I added these because I also use a reverse-proxy and can configure individual domains there.

Within local networks I think this may be useful as we can define any arbitrary FQDN for some service running.
So adding some A entries for local networks is probably the main use-case for this
(or redirecting DNS queries to some other server on the Internet).