swh-graph optimization: bypass edge restriction checks when edges=*

this is useful in general, but will also help with benchmarking (#1885 (closed)) as passing edges=* we will be able to time "pure" graph traversal without having to add timing counters around int→type maps (doing so will probably cost //more// than the lookups themselves)

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Migrated from T1922 (view on Phabricator)