feat(catalog): add S3Tables support with unit tests

- Integrate S3Tables catalog into catalog loader: add S3TablesCatalogBuilder to CATALOG_REGISTRY, add iceberg-catalog-s3tables dependency to loader, update workspace dependencies to include s3tables catalog

- Refactor catalog factory functions: replace separate factory functions with inline closures, simplify CATALOG_REGISTRY definition, improve maintainability for adding new catalog types

Author: fvaleye