bigquery storage_uri updates

[colin-rogers-dbt]

Split off file_format + base testing into: #1134
BigQuery Catalog Config will now support the following:

"name": "basic_iceberg_catalog_integration",
"catalog_type": "generic",
"file_format": "parquet",
"table_format": "iceberg",
"external_volume": "gs://my_bucket",

we then generate storage_uri based like "<external_volume>/_dbt/<schema>/<model>"

Model Config will now support changing this behavor
Full override via specifying storage_uri:

{{ config (
     "catalog": basic_iceberg_catalog_integration
      "storage_uri": "gs://my_different_bucket" # overrides the external volume
      )
 }}

OR
mirroring the functionality in dbt-snowflake, override the _dbt signifier with base_location_root:

{{ config (
     "catalog": basic_iceberg_catalog_integration
      "base_location_root": "different" # gs://my_bucket/different/<schema>/<model>
      )
 }}

dependent on: dbt-labs/dbt-core#11695

resolves #
docs dbt-labs/docs.getdbt.com/#

Problem

Solution

Checklist

• I have read the contributing guide and understand what's expected of me
• I have run this code in development and it appears to resolve the stated issue
• This PR includes tests, or tests are not required/relevant for this PR
• This PR has no interface changes (e.g. macros, cli, logs, json artifacts, config files, adapter interface, etc) or this PR has already received feedback and approval from Product or DX

[github-actions]

Thank you for your pull request! We could not find a changelog entry for this change in the dbt-adapters package. For details on how to document a change, see the Contributing Guide.

[github-actions]

Thank you for your pull request! We could not find a changelog entry for this change in the dbt-bigquery package. For details on how to document a change, see the Contributing Guide.

[github-actions]

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[github-actions]

Thank you for your pull request! We could not find a changelog entry for this change in the dbt-snowflake package. For details on how to document a change, see the Contributing Guide.

[mikealfare]

One and a half concerns and one nit.