certbot(role): support DNS-01 certs using acme-dns

Introduce new configuration structure called certbot__certs, which
allows for different challenge types per cert with the first challenge
type supported being dns-01-acme-dns.

roles/certbot/tasks/main/http_01_cert.yaml

@@ -0,0 +1,24 @@
+- name: get expiry date before
+  ansible.builtin.command: /usr/bin/openssl x509 -enddate -noout -in /etc/letsencrypt/live/{{ item }}/fullchain.pem
+  ignore_errors: true
+  become: true
+  changed_when: false
+  register: certbot__cert_expiry_before
+
+- name: obtain the certificate using certbot
+  ansible.builtin.command: /usr/bin/certbot certonly --keep-until-expiring --agree-tos --non-interactive --email "{{ certbot__acme_account_email_address }}" --no-eff-email --standalone --http-01-port "{{ certbot__http_01_port }}" -d "{{ item }}"
+  become: true
+  changed_when: false
+
+- name: get expiry date after
+  ansible.builtin.command: /usr/bin/openssl x509 -enddate -noout -in /etc/letsencrypt/live/{{ item }}/fullchain.pem
+  become: true
+  changed_when: false
+  register: certbot__cert_expiry_after
+
+# Doesn't work anymore. Dunno why.
+# TODO: Fix
+# - name: potentially report changed
+#   ansible.builtin.debug:
+#     msg: "If this reports changed, then the certificate expiry date and therefore the certificate changed."
+#   changed_when: certbot__cert_expiry_before.stdout != certbot__cert_expiry_after.stdout