[trace] fix the graph extraction tracing of complex AS hierarchies

details:
- now it is harder to configure simgrid traces for the graph visualization
by hand, but since simgrid tracing creates them automatically with
parameters for that extent, it should be okay.
- these complex link names are exposed in the graph configuration
generated with --cfg=triva/uncategorized:uncat.plist and
--cfg=triva/categorized:cat.plist