feat(datafusion): populate partition stats in $manifests system table

[QuakeWang]

Purpose

The DataFusion $manifests system table already defines min_partition_stats and max_partition_stats, but currently returns NULL for both columns. This change decodes the partition stats stored in ManifestFileMeta and renders them with Java-compatible row cast semantics.

Brief change log

• Add a DataFusion-internal formatter for Java-style BinaryRow row-to-string output.
• Populate $manifests.min_partition_stats and $manifests.max_partition_stats.
• Avoid formatting partition stats when the columns are not projected.
• Handle empty stats bytes for unpartitioned tables, all-null partition stats, and unknown stats.
• Add focused formatter tests and a DataFusion integration test for partition stats.

Tests

API and Format

Documentation