test: Configure Molecule testing framework

- Add comprehensive converge playbook with test scenarios
- Create Molecule configuration for role testing
- Set up verification tasks

tasks/main.yml

@@ -4,6 +4,7 @@
   ansible.builtin.apt:
     name: "{{ bind9_packages }}"
     state: present
+    cache_valid_time: 3600
   tags:
     - bind9
     - packages