Interleave for String Views duplicates buffers #11280

Describe the bug

When investigating some shortcomings in apache/datafusion#23565 I found that the interleave method doesn't reuse existing buffers, and clones them.

While this is fine for memory/perf, since cloning a buffer is a refcount rather than a full data clone, the problem arises in things that don't know about this accounting:

• The issue as is in DF, writing out IPC can inflate the output drastically & gc() can make things much worse
• BatchCoalescer gc check can inflate values as well

To Reproduce

use arrow::array::{Array, AsArray, StringViewArray};
use arrow::compute::interleave;

let array = StringViewArray::from_iter_values(
    (0..4).map(|i| format!("a string long enough to not be inlined {i}")),
);
assert_eq!(array.data_buffers().len(), 1);

let a = array.slice(0, 2);
let b = array.slice(2, 2);
let result = interleave(&[&a, &b], &[(0, 0), (1, 0), (0, 1), (1, 1)]).unwrap();

// fails: the single shared buffer is emitted twice
assert_eq!(result.as_string_view().data_buffers().len(), 1);

The effect grows with the number of inputs sharing buffers. Interleaving all 8192 rows of a StringViewArray (5 data buffers, 638,976 bytes) back from k equal slices:

Expected behavior

I'd expect interleave to reuse existing view buffers

Additional context

No response