Enable incremental read

[xanderbailey]

Which issue does this PR close?

• Closes Support incremental reads between snapshot-ids #2152

What changes are included in this PR?

This PR adds incremental snapshot scanning support to iceberg-rust, similar to the Java client's IncrementalDataTableScan. This feature allows reading only the data files that were added between two snapshots, which is essential for:

• Change data capture (CDC) pipelines - difference but related
• Incremental data processing
• Efficiently reading only new data since a checkpoint

Core Iceberg Changes (crates/iceberg/src/scan/)

New API on TableScanBuilder:

// Scan changes between two snapshots (from exclusive, to inclusive)
table.scan()
    .from_snapshot_exclusive(from_id)
    .to_snapshot(to_id)
    .build()?;

// Scan changes with inclusive from
table.scan()
    .from_snapshot_inclusive(from_id)
    .to_snapshot(to_id)
    .build()?;

// Convenience methods (matching Java API)
table.scan().appends_after(from_id).build()?;
table.scan().appends_between(from_id, to_id).build()?;

Implementation details:

• Added SnapshotRange struct to validate snapshot ancestry and track snapshot IDs in range
• Modified ManifestFileContext to filter entries with status=ADDED and snapshot_id within range
• Validates that only APPEND operations are in the snapshot range (matches Java behavior)
• Returns clear error if from_snapshot is not an ancestor of to_snapshot

DataFusion Integration (crates/integrations/datafusion/)

New constructors on IcebergStaticTableProvider:

// Scan changes between two snapshots
let provider = IcebergStaticTableProvider::try_new_incremental(table, from_id, to_id).await?;

// Scan with inclusive from
let provider = IcebergStaticTableProvider::try_new_incremental_inclusive(table, from_id, to_id).await?;

// Scan all appends after a snapshot to current
let provider = IcebergStaticTableProvider::try_new_appends_after(table, from_id).await?;

// Register with DataFusion and query
ctx.register_table("changes", Arc::new(provider))?;
let df = ctx.sql("SELECT * FROM changes WHERE category = 'A'").await?;

Example Added (crates/examples/)

Added datafusion_incremental_read.rs example demonstrating:

• Incremental reads between two snapshots
• Using appends_after() for checkpoint-based processing
• Combining incremental reads with SQL filters

Files Changed

File	Changes
crates/iceberg/src/scan/mod.rs	Added SnapshotRange, incremental scan methods on TableScanBuilder
crates/iceberg/src/scan/context.rs	Added snapshot_range to contexts, manifest entry filtering
crates/integrations/datafusion/src/table/mod.rs	Added incremental constructors to IcebergStaticTableProvider
crates/integrations/datafusion/src/physical_plan/scan.rs	Updated IcebergTableScan and get_batch_stream()
crates/examples/src/datafusion_incremental_read.rs	New example
crates/examples/Cargo.toml	Added datafusion dependencies and example entry

Are these changes tested?

Yes, this PR includes comprehensive tests:

Core Iceberg Tests (crates/iceberg/src/scan/mod.rs)

• test_incremental_scan_mutually_exclusive_with_snapshot_id - Verifies snapshot_id and incremental options are mutually exclusive
• test_incremental_scan_invalid_from_snapshot - Verifies error when from is not ancestor of to
• test_incremental_scan_invalid_to_snapshot - Verifies error for non-existent to_snapshot
• test_appends_after_convenience_method - Tests the convenience method
• test_appends_between_convenience_method - Tests the convenience method
• test_incremental_scan_from_snapshot_inclusive - Tests inclusive from behavior
• test_incremental_scan_from_snapshot_exclusive - Tests exclusive from behavior

DataFusion Integration Tests (crates/integrations/datafusion/src/table/mod.rs)

• test_static_provider_incremental_creates_scan - Verifies scan parameters are set correctly
• test_static_provider_incremental_inclusive - Tests inclusive flag
• test_static_provider_appends_after - Tests appends_after configuration
• test_static_provider_incremental_invalid_snapshot - Tests error handling

All existing tests continue to pass (41 scan tests, 8 static provider tests).