Warehouse path is always required for Glue catalog, even when there isn't one

[omerhadari]

The warehouse config prop for Glue catalog is required, but it isn't always known or required. The Glue catalog ID is enough in order to resolve metadata locations.

Moreover - I don't think this path is used for anything but protocol (FileIO type) inference? I was able to work around this issue by passing the correct Glue catalog ID (which is the AWS account ID) and s3:// as the warehouse, with no issue.

In my opinion warehouse should be replaced with something like FileIO type and only the Glue catalog ID should be required, but for backwards compatibility not passing warehouse should at least be allowed.

[CTTY]

I think this makes sense and making the warehouse path optional matches the iceberg-java behavior. We should probably fix this while implementing the new catalog builder: #1259

[chasehaddleton]

I believe there is an entire class of bugs caused by the current behavior. For example, if you pass s3 as the warehouse, but the catalog contains tables with both s3 and s3a files, then it erroneously fails saying that protocols do not match (even though it is immaterial). Moving to a FileIOType could solve this, assuming it's paired with a set of "valid protocols for a type".