Introduce new "configurator" for configuring devices, and templatize mgmt interface configuration

[Mierdin]

The discussion in nre-learning/antidote-core#93 illustrated the need to make the management IP address for devices more predictable, since the existing model of configuration hard-coded the same management address behind a NAT, so we could always use the same one.

However, this model proves problematic when you want to do more advanced things like streaming telemetry out of the management interface. The new vqfx-full image contributed by @mwiget instead, maps the em0 port directly to the outer container's eth0 interface, sharing its dynamically configured IP address, but because this is dynamically assigned by the CNI plugin, it's impossible to predict ahead of time with baked-in address configurations.

This PR introduces a new docker image intended to be used by Syringe to configure network devices. It works similar to the legacy one antidotelabs/napalm, but instead adds additional logic for passing dynamic data into a configuration template before applying it to the device. This allows us to totally templatize the management interface configuration for all devices, and pass it in by first retrieving the current address, and placing this data into any new proposed template. This PR also converts all existing network configurations to include this templatized parameter.

nre-learning/antidote-core#93 will now be converted purely to leverage the use of this image, without compromising on the current model of using the NAPALM replace strategy, which is a good practice to ensure atomicity between labs.