TableScan plan without projection is not converted correctly to a sql statement

[LatrecheYasser]

Describe the bug

when converting a plan that contains a table scan without a projection like this

TableScan: table

to a sql using plan_to_sql, it gives a wrong select statement

SELECT FROM table

where the * is missing.

To Reproduce

you can reproduce it by simply running

 let schema = Schema::new(vec![
            Field::new("id", DataType::Utf8, false),
            Field::new("value", DataType::Utf8, false),
 ]);

 let plan = table_scan(Some('table'), &schema, None)
                 .unwrap()
                 .build()
                 .unwrap();
 let sql = plan_to_sql(&plan).unwrap();
// sql will be set to `SELECT FROM table`

Expected behavior

when a plan doesn't have a projection node, the SQL query should look like
SELECT * FROM table

Additional context

No response