Use same ID for merged nodes for rev counterpart
Use same ID for merged nodes for rev counterpart

If the graph is symmetric, try to give the node (segment ID) for
the new merged reads node the same as its reverse complement
counter part.

This is useful when outputting the graph to GFA2, where each
segment is listed only once (whether it's a reverse complement or
not).

AbeelLab/phasm,AbeelLab/phasm