Decimal PrimitiveArray change datatype after try_unary

[jackwener]

Describe the bug

To Reproduce

        let a = Decimal128Array::from(vec![1, 3, -44, 2, 4])
            .with_precision_and_scale(9, 6)
            .unwrap();

        let f: PrimitiveArray<Decimal128Type> = a.unary(|i| i.add(1));

datatype from (9, 6) -> (38, 10)

Expected behavior

Additional context

[tustvold]

Possibly related to #3307

[viirya]

That is default datatype. In unary, it doesn't keep parameter of datatype e.g. precision/scale and timezone, I think.