Use "table name" as the property value on the index (instead of class name)

[andyjefferson]

When we create a Node we currently put it into the index for the class in question, as

db.index().forNodes("DN_TYPES").add(node, "class", className);

If the table name is specified we likely should do

db.index().forNodes("DN_TYPES").add(node, "class", tableName);

Note that, to find the object in a polymorphic query, if the class has persistable superclasses then we also put it with that class too, so would need to use the table name of the superclass in that case also