Allow Importing Multiple Documents from a single GCS Path

[holtskinner]

Inspired by https://stackoverflow.com/a/77609221/6216983

Thefrom_gcs() method can only create a single Wrapped Document from a single document output in GCS.

It could be simpler for users if this method could output a list of Wrapped Documents from a GCS path similar to from_batch_process_operation() and from_batch_process_metadata().

However, this would be backwards incompatible, so an alternative is to create a new method for this functionality. (Not sure what the best name would be)