Replace per-catalog-type Druid classes with CatalogUtil.buildIcebergCatalog

[Shekharrajak]

Collapse LocalCatalog, HiveIcebergCatalog, GlueIcebergCatalog, RestIcebergCatalog
into a single property-map-driven catalog backed by org.apache.iceberg.CatalogUtil.buildIcebergCatalog(name, options, conf).

Motivation

• Current code re-implements per-catalog setup that Iceberg already provides
• 4 hand-written classes → 1 generic class
• Gain free support for nessie, jdbc, bigquery and any future Iceberg catalog
• Allow custom catalog-impl=... for organizations with private catalogs

[Shekharrajak]

Please assign to me, I will work on it.