`CAST` should not change the name of an expression

[andygrove]

Is your feature request related to a problem or challenge? Please describe what you are trying to do.

DataFusion differs from Spark and Postgres in the naming of CAST expressions. Spark and Postgres casts do not rename the column.

Spark

scala> spark.sql("select id*2, cast(id as string), name from t").show()
+--------+---+-----+
|(id * 2)| id| name|
+--------+---+-----+
|       2|  1|hello|
|       4|  2|    x|
+--------+---+-----+

Postgres

postgres=# select id*2, cast(id as varchar(12)), name from t1;
 ?column? | id | name 
----------+----+------
        2 | 1  | x

DataFusion

❯ select id*2, cast(id as varchar(12)), name from test;
+---------------------------+-----------------------+-------+
| test.id Multiply Int64(2) | CAST(test.id AS Utf8) | name  |
+---------------------------+-----------------------+-------+
| 2                         | 1                     | hello |
+---------------------------+-----------------------+-------+

Describe the solution you'd like
cast should not change expression name in results

Describe alternatives you've considered
None

Additional context
None