add support for GCS warehouses in iceberg

[bsmithgall]

Description

Add GoogleCloudStorageInputSourceFactory to allow reading Iceberg data files from gs:// paths with "warehouseSource": "google". Add iceberg-gcp and google-cloud-storage dependencies to iceberg extension.

Also adds relevant tests and documentation updates.

Release note

new: allow Druid to read iceberg files from GCS

---

Key changed/added classes in this PR

• GoogleCloudStorageInputSourceFactory

---

This PR has:

• been self-reviewed.
• added documentation for new or modified features or behaviors.
• a release note entry in the PR description.
• added unit tests or modified existing tests to cover new code paths, ensuring the threshold for code coverage is met.
• added integration tests. (would love to tackle Add Integration tests for Iceberg connector #18017 but am not entirely sure what you'd like me to get that started. Testcontainers?)

[a2l007]

Thanks for the PR @bsmithgall ! Is this compatible with all the supported Iceberg catalogs?

[bsmithgall]

As far as I understand it should be; this just includes wiring for GCS to be a warehouseSource and doesn't touch the related icebergCatalog code. In IcebergInputSource.retrieveIcebergDatafiles(), the input source is created and then referenced. So by catalogue then:

• Hive: should be supported as outlined in the the documentation by setting the io-impl configuration to org.apache.iceberg.gcp.gcs.GCSFileIO.
• Rest: should be supported since it abstracts away storage
• Glue: probably not relevant since it's an AWS product, but I suppose it would probably still work in the same manner as the Hive catalog
• Local: not relevant for our case I don't think