`external.addresses` isn't used by external-dns

[vuldin]

What happened?

I'm setting the domain and addresses in the external section of the helm chart:

    external:
      domain: pnda.sh
      addresses:
        - redpanda-0-dev-ap-southeast-2
        - redpanda-1-dev-ap-southeast-2
        - redpanda-2-dev-ap-southeast-2

I'm also using external-dns annotations so A records get created for each broker. These records get created, but instead the records are for:

1. redpanda-0.pnda.sh
2. redpanda-1.pnda.sh
3. redpanda-2.pnda.sh

What did you expect to happen?

These should be using the details provided in the external section above.

How can we reproduce it (as minimally and precisely as possible)?. Please include values file.

```console $ helm get values -n --all # paste output here ```

Anything else we need to know?

No response

Which are the affected charts?

Redpanda

Chart Version(s)

```console $ helm -n list # paste output here ```

Cloud provider

JIRA Link: K8S-311