feat(arrow-array): add from_iter for DictionaryArray for building BinaryDictionaryArray

[rluvaton]

Which issue does this PR close?

make it easier to write tests for #6923

Rationale for this change

You can't build BinaryDictionaryArray from iterator of bytes

What changes are included in this PR?

added from_iter from iterator of &[u8] and from iterator of Option<&[u8]>

Are there any user-facing changes?

Yes.

There are breaking changes, see the failing example below with the fix:

#[test]
fn test_dictionary_all_string_nulls() {
-   let test = vec![None, None, None];
+   let test = vec![None::<&str>, None::<&str>, None::<&str>];
    let array: DictionaryArray<Int32Type> = test.into_iter().collect();
    array
        .into_data()
        .validate_full()
        .expect("All null array has valid array data");
}

---

I'll fix the broken tests when I know this change is desired

[wiedld]

The Extend<Option<V>> uses append_option. Hence the two FromIterator impls here. 👍🏼

[wiedld]

There is another FromIterator<Option<&'a str>> for DictionaryArray<T> for strings, which at first glance looks possible to combine. (Both use the GenericByteDictionaryBuilder with either strings, or bytes). Have you tried that, and do you think it's worthwhile?

[wiedld]

Tests are not yet fixed since @rluvaton wanted to confirm it was worthwhile. @alamb -- see comments above, hopefully it speeds up your review.

[alamb]

TLDR is that the idea is a good one -- thank you @rluvaton and @wiedld for the review

In general, I think the most important thing is to make sure this isn't a breaking change, otherwise we can't merge it until Feb due to the current release schedule: https://github.com/apache/arrow-rs?tab=readme-ov-file#release-versioning-and-schedule