Rename bc-network-admin-helper.rb to network-json-validator

This is a much better name now that it does many more things.
network-json-validator: Do not require the use of --admin-ip

It's already useful to validate without this.
network-json-validator: Fix bmc/bmc_vlan checks

These networks don't need to be part of the admin network. But they need
to be the same network.
network-json-validator: Fix error string

It was not using the right variables.
network-json-validator: Validate that VLAN ID is present
network-json-validator: Fix un-raised errors
network-json-validator: Additional bmc/bmc_vlan validation

When bmc network is different from admin network, then it needs to use a
vlan, and bmc_vlan must be using the same configuration.
network-json-validator: Also validate the vlan id
network-json-validator: Add validation for conduits
network-json-validator: Validate conduits used by networks