BatchCoalescer: add push_batch_interleaved #11141

BatchCoalescer already has push_batch_with_indices(batch, indices: &dyn Array) for the single-batch take case. There is no equivalent for the multi-batch case.

Callers that need to gather rows from multiple source batches must today call interleave_record_batch (copy 1) and then push_batch the result (copy 2). The intermediate batch is immediately discarded.

Proposed API

/// Semantically equivalent to `interleave_record_batch(batches, indices)`
/// followed by `push_batch`, without the intermediate RecordBatch allocation.
pub fn push_batch_interleaved(
    &mut self,
    batches: &[RecordBatch],
    indices: &[(usize, usize)], // (batch_idx, row_idx)
) -> Result<(), ArrowError>

Known callers in DataFusion that would benefit (tracked in apache/datafusion#25515):

• Top-K; TopKHeap::emit_with_state calls interleave_record_batch to reconstruct k surviving rows from the RecordBatchStore, then immediately pushes the result to a BatchCoalescer.
• Hash join / nested loop join; build_batch_from_indices or interleave_record_batch to materialize matched row pairs (copy 1), then push to the coalescer (copy 2).
• Sort merge join; join rows go through a materialization step before reaching the coalescer.