Introduce tests for supported features

[mrc0mmand]

Tracker for features we should have covered by a test case:

• [x] Basic boot ~~(included to have at least one ticked checkbox)~~
• [x] LVM (#8)
• [x] LUKS (#8)
• [x] LUKS + LVM (#8)
• [x] iSCSI (#8) (temporarily disabled)
• [ ] NFS (ip=dhcp, ip=<ipv4>, ip=<ipv6>, ...)
• [ ] NVMe over TCP
• [ ] RAID setups
• [ ] multi-NIC setups
  • [ ] bonding
  • [ ] vlans
• [ ] any combination of the above
• [ ] ???