Results column names should match SELECT clause expression names

When printing SQL SELECT results, Flink will output generated expression name when the expression is not column reference or used with alias/over.
For example, select a, a + 1 from T would result in

+----+-------------+-------------+
| op |           a |      EXPR$1 |
+----+-------------+-------------+
| +I |           1 |           2 |
| +I |           1 |           2 |
| +I |           1 |           2 |
+----+-------------+-------------+

Instead of the generated EXPR$1 it would be nice to have a + 1 (which is the case in some other data processing systems like Spark).