[core] Enable bundle writes in append-only compaction

[jianguotian]

Purpose

Append-only compaction currently consumes every reader batch row by row, even when a format reader can expose the complete logical batch as BundleRecords.

This PR adds a format-neutral Core bridge for bundle-capable compaction readers:

• Introduce BundleRecordIterator to expose all unconsumed logical rows as a borrowed bundle.
• Let BaseAppendFileStoreWrite.compactRewrite write such bundles directly, while always releasing each batch and closing the reader on success or failure.
• Preserve bundle iterator capabilities only through a full identity mapping. Projection/reordering, partition injection, row tracking, and ordinary iterators keep the existing row fallback.

This PR intentionally provides only the Core bridge. Format-specific bundle producers and direct writers can be added in follow-up PRs.

This complements #9660, which adds a Parquet row-group copy fast path. Both touch BaseAppendFileStoreWrite, so the PR merged second may need a small rebase.

Tests

• JDK 8: ColumnarRowIteratorTest and BaseAppendFileStoreWriteTest (8 tests passed).
• JDK 11: ColumnarRowIteratorTest and BaseAppendFileStoreWriteTest (8 tests passed).
• Covered identity versus transformed mappings, direct bundle writes, borrowed-batch release after write failure, and row fallback for stateful row-tracking iterators.