[BUG] Number of Sampled Nodes in Hop 0 is Wrong for LinkNeighborLoader

[alexbarghi-nv]

The LinkNeighborLoader is guessing the number of sampled nodes in hop 0 by looking at outgoing edges, which results in the wrong number of destinations being selected. In the worst case, this results in an overestimate of the destination type, which does not break most workflows. However, it should still be fixed.