comma-separated lists within arrays do not work with split_ip_by_version

[arusso]

Providing the following input to split_ip_by_version, you'll get all failures.

$input = [ '10.0.0.0/8,192.168.0.0/24', '172.16.0.0/12' ]
$output = split_ip_by_version($input)
size($output['other']) # == 1
size($output['4']) # == 1
size($output['6']) # == 1

We should be smart enough to break up the the lists, much like we flatten embedded arrays.

This comes up in hiera, when we do something like:

---
some_network: '10.0.0.0/8'
our_networks: '192.168.0.0/24,'172.16.0.0/12'

profile::firewall::rules:
  'some rule':
    protocol: tcp
    source:
      - "%{hiera('some_network')}"
      - "%{hiera('our_networks')}"