[Rust][DataFusion] Min/Max are not supported for timestamp types

> show columns from t;
+---------------+--------------+------------+-------------+-----------------------------+-------------+
| table_catalog | table_schema | table_name | column_name | data_type                   | is_nullable |
+---------------+--------------+------------+-------------+-----------------------------+-------------+
| datafusion    | public       | t          | a           | Utf8                        | NO          |
| datafusion    | public       | t          | b           | Timestamp(Nanosecond, None) | NO          |
+---------------+--------------+------------+-------------+-----------------------------+-------------+
2 row in set. Query took 0 seconds.
> select sum(b) from t;
Plan("Coercion from [Timestamp(Nanosecond, None)] to the signature Uniform(1, [Int8, Int16, Int32, Int64, UInt8, UInt16, UInt32, UInt64, Float32, Float64]) failed.")