No meaningful DFG/EOG queries possible which consider the overlay graph

[KuechA]

We cannot have any assumptions on the existence of DFG and EOG queries and also have to consider that they may loop between the overlay and underlying node (see concept discussed in #1994 ). This is a challenge for the DFG and EOG queries and extensions which are likely to return meaningless results.

Workaround: Do not use the overlay nodes in queries. However, this won't work if we have a requirement on the DFG which do not end up in the underlying node but are only present as a DFG to the overlay node (i.e., the alwaysFlowsTo query won't work).

[oxisto]

Is this fixed by the EOG stuff in #2101 ?