Add support for reading graphs with PTHash instead of GOV
The name of the .order file when using a non-GOV MPH changed, in order to support more than one (mphf, permutation) pair for a given graph.
Staging instance, all changes can be removed at any time
The name of the .order file when using a non-GOV MPH changed, in order to support more than one (mphf, permutation) pair for a given graph.