Eval Local State includes entry for vertices filtered out by windows

[narnolddd]

When running an algorithm with eval local state, if the graph has been windowed in a way that vertices are removed by that window, an entry still exists for them in the local eval state. Example can be found here in the test_windowed_graph where the resulting windowed graph has 8 vertices but the local state has length 11. Have made a temp fix in there which skips over vertices that have empty state.