fix: sql test dont work in Postgresql because required alias

[benfdking]

Postgres doesn't like our current test generation because it doesn't have an alias

called `Result::unwrap()` on an `Err` value: QueryError { query: "error returned from database: subquery in FROM must have an alias", error: "SELECT id, COUNT(*)\nFROM (WITH\ntest_source AS (SELECT * FROM other_schema.test_table),\ntest_model AS (SELECT id FROM test_source)\nSELECT * FROM (SELECT id FROM test_model) AS alias)\nGROUP BY id\nHAVING COUNT(*) > 1;\n" }
thread 'databases_postgres::tests::postgres_sql_test' panicked at rust/quary-databases/src/databases_postgres.rs:839:54:
called `Result::unwrap()` on an `Err` value: QueryError { query: "error returned from database: subquery in FROM must have an alias", error: "SELECT id, COUNT(*)\nFROM (WITH\ntest_source AS (SELECT * FROM other_schema.test_table),\ntest_model AS (SELECT id FROM test_source)\nSELECT * FROM (SELECT id FROM test_model) AS alias)\nGROUP BY id\nHAVING COUNT(*) > 1;\n" }

[benfdking]

#262 fixes this issue in Postges