[Feature] Validate zone sources arguments (only support IP addresses)

[jcpunk]

Affected Puppet, Ruby, OS and module versions/distributions

• Puppet: 6
• Ruby: 2.7
• Distribution: Fedora
• Module version: 4.4.0

How to reproduce (e.g Puppet code you use)

  firewalld_zone { 'restricted':
    ensure           => present,
    target           => '%%REJECT%%',
    purge_rich_rules => true,
    purge_services   => true,
    purge_ports      => true,
    sources          => ['example.host.com', 'other.host.com'],
  }

What are you seeing

Firewalld rejects the hostname based source

What behaviour did you expect instead

The module would restrict the sources to Array[Stdlib::IP::Address]

Output log

Any additional information you'd like to impart