Preloads :id, and :name if available. Leaves everything else up to lazy-loading, though optionally can call a per-collection function to add more values if available
fence_mode can be 'isolated' (disconnected from EdgeGateway) or
'natRouted' (connected to NatService on EdgeGateway).
The network types differ significantly enough to have a separate
set of tests, to be expanded later.
This has also fixed an issue where undefined attributes in the
request output were not being unmarked as NonLoaded. Test adjusted
accordingly.
In addition, highlighted that we need the ensure_list! hack on
IpRanges->IpRange.