Move the generation of the list of ports to the server

Ref #676

tests/topologies/1_5_vmware/after/1_5_vmware.gns3

@@ -30,6 +30,9 @@
                 "name": "GNS3 VM",
                 "node_id": "9e06d0ce-e8df-4f38-bdfa-7c83e19a91c1",
                 "node_type": "vmware",
+                "port_name_format": "Ethernet{0}",
+                "port_segment_size": 0,
+                "first_port_name": null,
                 "properties": {
                     "acpi_shutdown": false,
                     "adapter_type": "e1000",