Introduce a new variable `f2b_unban_ip` in the Ansible playbook to allow users to specify an IP address that should be unbanned using Fail2Ban. This feature enhances the flexibility of the playbook by enabling targeted IP management.
This commit adds Fail2ban settings to `defaults/main.yml`, a new task to restart the fail2ban service, and a task file for deploying Fail2Ban integrated with Proxmox Firewall. The new tasks include checks, validations, and configuration to enhance security by blocking malicious IP addresses.
