TT#48194 Remove default/fallback validation for network interfaces

Current problem: CE system doesn't pass ngcpcfg
validation if interface name is 'ens0', installation
is aborted on the final 'ngcpcfg apply'.

There were a lot of code changes here and the original logic
if fallback validation has been lost.

The situation here is very unpleasant as all Jenkins tests
reported no issues for us, as interface name is 'eth0' there.

We have enabled validation be default in mr6.5, in the same
time the validation schema we have is not yet perfect, but
we must focus on 'trust' to validation functionality we
introduced otherwise it will not be used by users.

There is not point to have fallback in validation at this stage.
As it can be triggered for random physical and logical interfaces
in the system. Keep in mind mr6.5 generates /etc/network/interfaces
from network.yml, so all interfaces must be described in network.yml.

Change-Id: I1d90c64941bfb7eb8afad51c64c19f72b4ec65d9

sbin/ngcp-network-validator

@@ -161,10 +161,6 @@ foreach my $hostname (sort keys %{$yaml->{hosts}}) {
             $ifacemap->{mapping}->{vlan_raw_device}->{required} = 'yes';
         } elsif ($iface =~ m/^idrac/) {
             $ifacemap->{mapping}->{type}->{required} = 'yes';
-        } else {
-            $ifacemap->{mapping}->{type}->{required} = 'yes';
-            $ifacemap->{mapping}->{ip}->{required} = 'yes';
-            $ifacemap->{mapping}->{netmask}->{required} = 'yes';
         }
 
         # Consistency checks.