Introduce SMGHasValueEdges#getOverlappingEdges instead of SMGEdgeHasValueFilter#overlapsWith

Remove SMGEdgeHasValueFilter#overlapsWith

Introduce SMGHasValueEdges#getOverlappingEdges instead of SMGEdgeHasValueFilter#overlapsWith. Use the new method in most places. Add test to show that behavior has not changed.

In SMGState#readValue, replace #overlapsWith with another #getCoveringEdge to get explicitly the edge that covers the interesting bits instead of loop over overlapping ones.

In SMGState#writeValue0, use #contains instead of checking if the edge is present among the overlapping edges. The change is that a zero- value edge is seen as present as part of a bigger zero-value edge now, but we don't need to write it in this case anyway.