Cross-shard joins

[levkk]

Description

SELECT * FROM users INNER JOIN orders
ON order.not_sharding_key = users.not_sharding_key;

In this case, sending the query to all shards as-is produces the wrong result since values from shard A are not joined to values in shard B. We need to remove the join, get all rows, and re-apply the join in the pooler.