Update queries to properly showcase factorized join execution

[prrao87]

Updates

The aim of this PR is to showcase the power of Kùzu's factorized joins with the simplest queries possible. As a result, query 10 is removed, and queries 8 and 9 are rewritten as follows.

Query 8:
 
        MATCH (a:Person)-[r1:Follows]->(b:Person)-[r2:Follows]->(c:Person)
        RETURN count(*) AS numPaths
    

        Number of second-degree paths:
shape: (1, 1)
┌──────────┐
│ numPaths │
│ ---      │
│ i64      │
╞══════════╡
│ 58431994 │
└──────────┘
        

Query 9:
 
        MATCH (a:Person)-[r1:Follows]->(b:Person)-[r2:Follows]->(c:Person)
        WHERE b.age < $age_1 AND c.age > $age_2
        RETURN count(*) as numPaths
    

        Number of paths through persons below 50 to persons above 25:
shape: (1, 1)
┌──────────┐
│ numPaths │
│ ---      │
│ i64      │
╞══════════╡
│ 45632026 │
└──────────┘

This clearly showcases how effective Kùzu's factorized joins are when passing through nodes that have a lot of many-to-many relationships.