TransformingEncoder should work with primitive types

Currently using a primitive type on as input to a transforming encoder will fail with an exception like

```
Cause: java.lang.ClassCastException: class org.apache.spark.sql.catalyst.expressions.MutableAny cannot be cast to class org.apache.spark.sql.catalyst.expressions.MutableLong (org.apache.spark.sql.catalyst.expressions.MutableAny and org.apache.spark.sql.catalyst.expressions.MutableLong are in unnamed module of loader 'app')
```