flashstart: ipsets ranges not added and bypasses not working correctly

[Tbaile]

Steps to reproduce

Deploy the current NethSecurity system with FlashStart enabled.

Expected behavior

IP sets and bypass mechanisms should be added and function as expected without errors.

Actual behavior

If IP sets contain a range of IPs (using '-') they are not correctly added resulting in not sending dns requests where they should. Additionally if the IP is in the bypass and on a profile, it will get redirected anyway to flashstart, causing issues.

Components

ns-flashsstart 1.0.3-r2

[Tbaile]

QA requirements: Flashstart ProPlus with at least 2 profiles (one standard, one catch-all), client filtered by the service
QA:

1. Add a HostSet in the firewall's objects with range: 192.168.1.X-192.168.1.Y, make sure the client filtered is within these IPs
2. Wait until flashstart platform shows it within hybrid IPs, then add it to a profile, the profile should block something (make the profiles block different domains than one another, to allow you to check which profile is actually blocking you)
3. Check that the hostset is correctly saved by browsing the nft table nft list table inet fw4 and looking into the IPSets, otherwise you'll find something on the lines of 192.168.1.x/null
4. Check that your client is blocked by flashstart, the add the client to the bypasses through the FW UI.
5. Make sure you're not blocked anymore by flashstart.

[gsanchietti]

Fix already applied an tested on a production machine.

Ticket: https://helpdesk.nethesis.it/a/tickets/200236