Enhance property pruning rule

[czpmango]

At present, our property pruning optimization only considers the symbols between operators without analyzing specific expressions, so some statements that can be optimized may be ignored. The following statement can prune all properties.

MATCH (v1)-[e:like*1..5]->(v2)
WHERE id(v1) == "Tim Duncan"
RETURN count(v2)

This optimization can not only reduce rpc overhead but also reduce memory pressure during graphd computation.

[czpmango]

Fwiw, some simple aggregations like count(*) can be considered pushed down to the storage layer(Scan or Traverse operator). This may greatly improve the performance of statements like the above.