feat: Add BigQuery ObjectRef functions to bigframes.bigquery.obj

This change introduces support for BigQuery ObjectRef functions:
- `OBJ.FETCH_METADATA`
- `OBJ.GET_ACCESS_URL`
- `OBJ.MAKE_REF`

These are exposed via a new `bigframes.bigquery.obj` module.

Changes:
- Added `ObjMakeRefJson` operation in `bigframes/operations/blob_ops.py`.
- Updated `ObjGetAccessUrl` operation to support optional duration.
- Updated `bigframes/operations/__init__.py` to export new operations.
- Updated `bigframes/core/compile/ibis_compiler/scalar_op_registry.py` and `bigframes/core/compile/sqlglot/expressions/blob_ops.py` to support new operations.
- Created `bigframes/bigquery/_operations/obj.py` with the implementation of `fetch_metadata`, `get_access_url`, and `make_ref`.
- Created `bigframes/bigquery/obj.py` to expose the functions.
- Exposed `obj` module in `bigframes/bigquery/__init__.py`.
- Added unit tests in `tests/unit/bigquery/test_obj.py`.

Author: google-labs-jules[bot]

bigframes/bigquery/_operations/obj.py

@@ -27,12 +27,13 @@
 import numpy as np
 import pandas as pd
 
+from bigframes.core import log_adapter
 import bigframes.core.utils as utils
 import bigframes.operations as ops
 import bigframes.series as series
 
 
-@utils.preview(name="The ObjectRef API `fetch_metadata`")
+@log_adapter.method_logger(custom_base_name="bigquery_obj")
 def fetch_metadata(
     objectref: series.Series,
 ) -> series.Series:
@@ -48,7 +49,7 @@ def fetch_metadata(
     return objectref._apply_unary_op(ops.obj_fetch_metadata_op)
 
 
-@utils.preview(name="The ObjectRef API `get_access_url`")
+@log_adapter.method_logger(custom_base_name="bigquery_obj")
 def get_access_url(
     objectref: series.Series,
     mode: str,
@@ -80,7 +81,7 @@ def get_access_url(
     )
 
 
-@utils.preview(name="The ObjectRef API `make_ref`")
+@log_adapter.method_logger(custom_base_name="bigquery_obj")
 def make_ref(
     uri_or_json: series.Series,
     authorizer: Optional[series.Series] = None,