[IMPROVEMENT] Improve Asserts

Some assertions should be improved, for example:

            host-vm-1:
              disk_source: "/mnt/iso/debian10-terraform.qcow2"
              os_family: Debian
              cpu: 1
              memory: 512
              hypervisor: hypervisor_1
              ansible_host: 192.168.122.9
              network_interfaces:
                iface_1:
                  name: default
                  type: nat
                  ip: 192.168.122.9
                  gw: 192.168.122.1
                  dns:
                    - 192.168.122.1
              default_route: True <<<--- note this is unindented

This snippets passes the assertions even if it's not valid We should review and evaluate more corner cases to include in the assertions

Also we could think of an external tool/linter as @alegrey91 suggests to validate inventories