Create a "links" graph that strictly reflects the topology links

[ipspace]

The current "topology" graph does not exactly reflect the physical links in VLAN environments. It might be useful to have another graph that closely mirrors links (it's produced from the "links" list similarly to how we build the containerlab file)

See ipspace/netlab-examples#28 (reply in thread) for details

[ipspace]

The problem was the incorrect usage of "lan" network type instead of checking the number of devices attached to a segment. Implemented in #2547 and #2557