Make graph table name optional

[Dtenwolde]

Currently, the graph table requires an alias (or name?) at the end of it. Similar to a subquery. This is useful if you need to continue using the columns outside the graph table. However, if all you do is select column(s) from the graph table, the name at the end is not used.

Similar to the subquery, it should be optional to name the graph table. If it is not named, it should default to something like unnamed_graph_table (in case of multiple graph tables which will be supported in the future).

-FROM GRAPH_TABLE (snb
    MATCH (p:Person)-[w:workAt_Organisation]->(u:University)
    COLUMNS (p.id, u.id, u.type)
    )
    limit 10;

Should lead to unnamed_graphtable0