Unparser with PostgreSqlDialect fails after Optimization Pass

[cetra3]

Describe the bug

The Unparser has a bug in the way that it treats certain PostgreSQL formatted queries, after optimization, which seems to be because requires_derived_table_alias is true:

I.e, optimizing then unparsing this query with postgresql dialect breaks:

WITH base AS (SELECT name, salary FROM t)
SELECT name,
    CASE WHEN SUM(salary) > 0 THEN 1 ELSE 0 END AS x,
    CASE WHEN SUM(salary) > 0 THEN SUM(salary) ELSE 0 END AS y
FROM base GROUP BY name

To Reproduce

Here's a test we can add somewhere that fails:

#[tokio::test]
async fn test_cse_derived_projection_roundtrip() {
    let ctx = SessionContext::new();
    ctx.sql("CREATE TABLE t (name TEXT, salary DOUBLE) AS VALUES ('a', 1.0), ('b', 2.0)")
        .await.unwrap().collect().await.unwrap();

    let sql = "\
        WITH base AS (SELECT name, salary FROM t) \
        SELECT name, \
            CASE WHEN SUM(salary) > 0 THEN 1 ELSE 0 END AS x, \
            CASE WHEN SUM(salary) > 0 THEN SUM(salary) ELSE 0 END AS y \
        FROM base GROUP BY name";

    let df = ctx.sql(sql).await.unwrap();
    let optimized = ctx.state().optimize(df.logical_plan()).unwrap();
    let unparser = Unparser::new(&datafusion_sql::unparser::dialect::PostgreSqlDialect {});
    let unparsed = unparser.plan_to_sql(&optimized).unwrap().to_string();

    ctx.sql(&unparsed).await.unwrap_or_else(|e| {
        panic!("Roundtrip failed.\n\nOriginal: {sql}\nUnparsed: {unparsed}\nError: {e}")
    });
}

Expected behavior

This should parse correctly

Additional context

No response