implement new_null_array for view types

[XiangpengHao]

Which issue does this PR close?

Closes #5893 .

Rationale for this change

Very simple fix + very simple tests

As I start integrating view types in DataFusion, I expect more such unhandled cases to surface. Let me know if we want to do fine-grained case-by-case fix (like the current pr), or try to batch multiple fixes (so they won't flood people's notifications)...

What changes are included in this PR?

Are there any user-facing changes?

[alamb]

Thank you @XiangpengHao

As I start integrating view types in DataFusion, I expect more such unhandled cases to surface. Let me know if we want to do fine-grained case-by-case fix (like the current pr), or try to batch multiple fixes (so they won't flood people's notifications)...

I personally prefer multiple small PRs

BTW we should probably figure out how you will get these fixes into DataFusion as there won't be an arrow-rs release for a few weeks

Maybe it is time to create a datafusion "string-view-feature-branch" or something and pin to the head of arrow-rs 🤔

[alamb]

I also double checked that this function is what is used by new_null_array: https://docs.rs/arrow-array/52.0.0/src/arrow_array/array/mod.rs.html#668