test: Delta native scan test suites

- CometDeltaNativeSuite (26 tests): core reads, projections, filters,
  partitioning, schema evolution, time travel, complex types, primitives
- CometDeltaColumnMappingSuite (5 tests): column mapping name/id modes,
  deletion vectors, DV + column mapping, column mapping + schema evolution
- CometDeltaAdvancedSuite (11 tests): joins, aggregations, unions, window
  functions, DPP, DPP file pruning, planning metrics, scheme validation
- CometFuzzDeltaSuite: property-based testing with random schemas
- DeltaReadFromS3Suite: MinIO-based S3 integration tests
- CometDeltaTestBase: shared trait with helpers

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: schenksj