`exit_addresses` in `exit_node` stored in wrong format

exit_addresses in table exit_node has wrong format. At the moment we have comma separated values, it could be useful to make the column an array of strings for easier parsing:

• 22.22.22.22 should be ["22.22.22.22"]
• 22.22.22.22, 10.10.10.10, 11.12.13.14 should be ["22.22.22.22", "10.10.10.10", "11.12.13.14"]