PrimitiveDictionaryBuilder with specific value data type and capacity

[rluvaton]

Is your feature request related to a problem or challenge? Please describe what you are trying to do.
I want to create a PrimitiveDictionaryBuilder with custom capacity and specific data type for the values but I can't

#[test]
fn should_work() {
    let data_type = DataType::Dictionary(
        Box::new(DataType::Int32),
        Box::new(DataType::Timestamp(
            TimeUnit::Microsecond,
            Some("+08:00".into()),
        )),
    );

    let mut builder =
      PrimitiveDictionaryBuilder::<Int32Type, TimestampMicrosecondType>::with_capacity(1, 2);

    assert_eq!(builder.finish().data_type(), &data_type);
} 

This test fails with:

assertion `left == right` failed
  left: Dictionary(Int32, Timestamp(Microsecond, None))
 right: Dictionary(Int32, Timestamp(Microsecond, Some("+08:00")))

so I tried using new_from_builders

#[test]
fn should_work() {
    let value_data_type = DataType::Timestamp(
        TimeUnit::Microsecond,
        Some("+08:00".into()),
    );
    let data_type = DataType::Dictionary(
        Box::new(DataType::Int32),
        Box::new(value_data_type.clone()),
    );

    let mut builder =
      unsafe {
          PrimitiveDictionaryBuilder::<Int32Type, TimestampMicrosecondType>::new_from_builders(
              PrimitiveBuilder::with_capacity(1).with_data_type(DataType::Int32),
              PrimitiveBuilder::with_capacity(2).with_data_type(value_data_type),
          )
      };

    assert_eq!(builder.finish().data_type(), &data_type);
}

this works but I can't control the hash map capacity, and the keys and values are unnecessary iterated over (even if they are empty)

Describe the solution you'd like
Provide with_value_data_type function that will be similar to primitive_builder

so you could do:

let value_data_type = DataType::Timestamp(
    TimeUnit::Microsecond,
    Some("+08:00".into()),
);
let data_type = DataType::Dictionary(
    Box::new(DataType::Int32),
    Box::new(value_data_type.clone()),
);

let mut builder =
  PrimitiveDictionaryBuilder::<Int32Type, TimestampMicrosecondType>::with_capacity(1, 2)
    .with_value_data_type(value_data_type);

[tustvold]

Can you use https://docs.rs/arrow-array/latest/arrow_array/builder/struct.PrimitiveDictionaryBuilder.html#method.new_from_empty_builders ?

Edit: oh I see you are but it isn't picking up the data type, this IMO is a bug and should be an easy enough fix

[alamb]

label_issue.py automatically added labels {'arrow'} from #7012