Bring graph property queries inline with node/edges

[miratepuffin]

g = PersistentGraph()
g.add_node(1,1)
g.node(1).add_updates(1,{"weight":10})
g.node(1).add_updates(3,{"weight":20})
g.window(5,7).node(1).properties.temporal.get("weight")
#Returns (5,20)

g = PersistentGraph()
g.add_property(1,{"weight":10})
g.add_property(3,{"weight":20})
g.window(5,7).properties.temporal.get("weight").values()
#Returns nothing

[ljeub-pometry]

This is not fixed