Previously in from_avro/to_avro, we override the method `simpleString` and `sql` for the string output. However, the override only affects the alias naming:
, (mode,PERMISSIVE)) AS from_avro(col, struct<col1:bigint,col2:double>, Map(mode -> PERMISSIVE))#11]
It only makes the alias name quite long.
We should follow `from_csv`/`from_json` here, to override the method prettyName only, and we will get a clean alias name
... AS from_avro(col)#11