Greycat: GraphNodeWrapper equality should consider world+time+ID, not just ID

[agarciadom]

While writing a query, we noticed that if we compare a node in EOL with another version of the same node, it is reported to be equal. This should not be the case: GreycatNode explicitly compares world, time and ID in its equals method.

The GraphNodeWrapper is not reusing the equals method of the IGraphNode class. This should be revised, while making sure we preserve the same ID-based comparison that we had for Neo4j and OrientDB.